BUTTON 


DEPARTMENT  OF  VOCATIONAL  EDUCATION 

GENERAL  EDITOR 

FRED  D.  CRAWSHAW,  M.E. 

PROFESSOR  OF  MANUAL  ARTS    THE  UNIVERSITY  OF   WISCONSIN 


MECHANICAL  DRAWING 

FOR  INDUSTRIAL  AND 
CONTINUATION  SCHOOLS 


BY 

PHILIP  W.  HUTTON 

TEACHER  OF  DRAWING  AND  WOOD-WORKING,  CHICAGO   PUBLIC  SCHOOLS 


SCOTT,  FORESMAN  AND  COMPANY 
CHICAGO  NEW  YORK 


COPYRIGHT  1915 
BY  SCOTT,  FORESMAN  AND  COMPANY 


EDITOR'S  NOTE 

In  commercial  shop  and  construction  work  a  mechanically  drawn 
plan  invariably  accompanies  the  work  of  construction.  Such  a  plan 
is  the  chief  means  of  giving  information  to  mechanics  concerning  work 
to  be  done.  Upon  their  ability  to  read  and  properly  interpret  these 
drawings  will  depend  the  accuracy  of  construction  and  the  proper 
assembling  of  parts. 

In  learning  a  trade  under  ordinary  commercial  conditions  only 
incidental  practice  is  afforded  in  reading  drawings.  Experience  has 
shown,  however,  that  when  such  practice  is  an  integral  part  of  trade 
instruction,  proficiency  in  tool  operations  comes  more  quickly  and 
surely. 

One  of  the  most  satisfactory  methods  of  learning  to  read  draw- 
ings is  to  make  them.  Hence  it  is  desirable  in  the  preparation  for 
industrial  pursuits  that  students  be  given  a  simple  and  practical 
course  in  mechanical  drawing 

The  Author  has,  as  a  result  of  his  experience  in  trade  work  and 
industrial  teaching,  prepared  a  text  which  is  peculiarly  suitable  for 
use  in  continuation,  all-day  industrial,  and  evening  classes.  It  is  well 
arranged  to  enable  those  interested  in  a  particular  trade  to  become 
familiar  with  essential  drawings,  and  to  learn  how  to  make  them 
quickly  and  accurately. 

These  characteristics  should  recommend  the  book  to  those  in  charge 
of  industrial  work  in  schools,  including  high  schools. 

F.  D.  CRAWSHAW. 


2065916 


PREFACE 

The  arrangement  of  the  following  course  is  the  outgrowth  of  several 
years  of  experience  in  teaching  the  subjects  of  Mechanical  Drawing 
and  Industrial  Arts  to  boys  of  the  intermediate  grades. 

Since  the  organization  of  Industrial  Departments  in  the  schools  of 
Chicago,  the  author  has  taught  an  average  of  one  hundred  boys  per  day 
and  has  given  his  whole  time  and  attention  to  Mechanical  Drawing. 

Having  had  years  of  experience  as  a  practical  wood-worker  and 
mechanical  draftsman,  he  has  applied  this  practical  experience  to  the 
school  room.  He  has  endeavored  to  make  drafting  interesting  by 
making  it  practical. 

Exercises  and  fundamental  and  essential  conventions  have  been  com- 
bined in  practical  problems  suitable  for  those  engaged  in  various  lines  of 
industrial  work.  These  follow  an  elementary  course  on  principles  wliicli 
should  be  mastered  by  all  beginners.  The  special  industrial  courses 
following  the  elementary  course  may  be  taken  with  profit  by  all. 
However,  beginning  with  SHEET  METAL  WORK,  each  course  is  prepared 
with  reference  to  peculiar  industrial  interests.  Up  to  this  point  the 
work,  as  outlined,  should  be  regarded  as  a  unit. 

The  purpose  of  the  author  has  been : 

(1)  To  arrange  a  course  especially  adapted  to,  and  within  the  limit 

of,  a  boy's  ability. 

(2)  To  give  the  boy  an  intelligent  idea  of  what  a  mechanical  drawing 

is  for,  how  to  make  it,  and  how  to  read  and  work  from  one  made 
by  others. 

(3)  To  awaken  an  interest  in  the  common  industries  of  life,  and  to 

create  a  desire  for  as  complete  an  education  along  industrial 
lines  as  possible. 

If  the  boy  is  to  enter  industrial  life  at  an  early  age,  the  course  in 
drafting  herein  outlined  will  give  him  a  foundation  for  his  life  duties 
far  beyond  that  of  the  average  mechanic. 

The  course  is  both  logical  and  practical. 

PHILIP  W.  HUTTON. 


[4] 


CONTENTS 

PAGE 

Editor's  Note   3 

Preface    4 

Introduction    7 

Equipment 9 

Description,  Care,  and  Use  of  Tools 10 

Lines  to  Use 22 

Lettering    24 

Drill  in  Use  of  Instruments 27 

Exercise       I— Lay  Out  of  Sheet 28 

Exercise     II — Basket  Weave 32 

Exercise  III — Application  of  Basket  Weave   34 

Exercise    IV — Circular  Weave  36 

Exercise      V — Straight  Lines  Tangent  to  Arcs  of  Circles 38 

Exercise   VI — Arc   Tangents    40 

Projection  Drawing 43 

Projection  I — Cube  44 

Projection  II — Wedge  48 

Projection  III — Hexagonal  Prism 49 

Approximate  and  True  Ovals 53 

Projection  IV — Cast  Iron  Ring 54 

Section  Lines 56 

Projection  V — Pipe  Cut  at  an  Angle 58 

Projection  VI — Cone  Cut  Parallel  to  Its  Axis 62 

Wood- Working   Drawings    65 

Drawing  Board    66 

Pin  Tray 68 

Clothes  Line  Reel   70 

Clothes  Lifter 72 

Foot  Rest 74 

Shelf,   Sleeve   Ironing  Board,   Mail  Box,   Book  and 

Magazine  Rack    77 

Pedestal   .  86 


PAGE 

Inking  and  Tracing 93 

Sheet  Metal  Drawing 9.~> 

Bread  Pan   96 

Dust  Pan  100 

Lawn  Sprinkler  102 

Water  Pail   104 

Sugar  Scoop  106 

Float  Ball  110 

Sink  Strainer  112 

Machine  Drawing 115 

Screw  Threads  116 

Hand  Wheel  120 

Plain   Bearing    122 

Wrench    122 

Monkey  Wrench  and  Wood  Workers'  Vise 124 

Architectural  Drawing 129 

Electrical  Conventions 145 

Problems  in  Electric  Wiring 151 

Bell  Wiring    152 

Gasoline  Engine  Wiring   154 

House  Wiring    154 

Gas  Plumbing  Conventions 156 

Problems  in  Pipe  Fittings 159 

Problems  in  Plumbing  165 

Hot  Water  Connections  166 

Lavatory  Connections 168 

Problems  in  Brick  Work  171 


[6] 


INTRODUCTION. 

A  mechanical  drawing  is  an  assembly  of  views  of  an  object  which 
show  the  length,  width,  thickness,  and  form  of  each  and  every  part  of  it. 
l>y  means  of  dimensions  and  notes,  the  size  of  each  part  and  the  material 
of  which  it  is  to  be  made  are  given.  In  fact,  a  mechanical  drawing  gives 
all  the  details  about  an  object  which  a  workman  or  series  of  workmen 
may  need  in  its  construction. 

Mechanical  Drawing  may  be  classed  as  a  universal  language  by 
which  the  designer  of  an  object  can,  through  a  drawing  of  it.  transmit 
Ids  ideas  clearly  to  the  man  or  men  who  are  to  make  it. 

In  the  construction  of  a  building,  or  a  bridge,  the  foundation  is  first 
laid.  So  it  is  in  the  study  of  Mechanical  Drawing.  The  use  and 
care  of  all  drawing  tools  must  first  be  thoroughly  understood.  After 
this,  some  general  principles  must  be  mastered.  These  principles  will 
not  be  given  all  at  once,  but  will  be  introduced  from  time  to  time  as 
a  need  for  them  arises  in  the  different  problems  to  be  worked  out. 

After  the  foundation  is  laid,  certain  fundamentals  must  be  given 
consideration,  such  as  the  work  an  object  has  to  perform,  the  use  to 
which  an  article  is  to  be  put,  etc.  These  fundamentals  are  effected  by: 

(1)  The  most  suitable  materials  for  strength,  wearing  ability,  etc., 

to  perform  the  desired  work. 

(2)  The  construction  to  be  used. 

(3)  The  design  or  shape,  so  as  to  make  the  object  pleasing  to  the  eye 

and  still  to  allow  it  to  perform  its  work. 


[7] 


EQUIPMENT 

The  necessary  equipment  consists  of  the  following: 

1  Drawing  Board 

1  T-Square 

1  30-degree  60-degree  Triangle,  8" 

1  45-degree  6" 

1  12"  Rule  graduated  to  sixteenths. 

1  Irregular  or  French  Curve 

1  Protractor 

1  Soft  red  rubber  Eraser 

1  Ink  Eraser 

1  Cleaning  Eraser 

1/2  dozen  Thumb  Tacks 

1  3H  Pencil 

1  4H  Pencil 

1  12"  Triangular  Scale  Rule 

1  Penholder 

1/2  dozen  fine  pointed  Pens.  (Gillotts  No.  303) 

1  Bottle  Drawing  Ink 

1  Drawing  Set  consisting  of  the  following: 

1  Compass  with  Lengthening  Bar,  Pencil,   and  Pen 

Points 
1  Divider 
1  Bow  Divider 
1  Bow  Pencil 
1  Bow  Pen 


[9] 


DESCRIPTION,  CARE,  AND  USE  OF  TOOLS 

The  selection  and  care  of  drawing  tools  and  instruments  must  be 
given  careful  thought  and  consideration. 

DRAWING    PENCILS 

By  referring  to  the  equipment  list  it  will  be  seen  that  two  pencils  of 
different  degrees  of  hardness  are  required.  The  degree  of  hardness  is 
designated  by  the  number  of  II 's  stamped  on  the  pencil.  Experience  has 
taught  that  the  HHH  and  the  HHIIH,  in  other  words  the  three  II  and 
four  II  pencils,  are  best  fitted  for  use  in  beginners'  hands.  The  more 
II's  the  pencil  has  the  harder  the  lead  is;  the  four  II  pencil  is,  therefore, 
harder  than  the  three  H.  The  three  II  pencil  sharpened  to  a  long 
round  point  (Fig.  I)  is  used  for  all  freehand  work,  such  as  the  making 
of  arrow  points,  figures,  etc.  The  four  II  pencil  sharpened  to  a  long 
wedge-shaped  point  (Fig.  I)  is  used  for  all  line  work  such  as  light 
construction  lines,  dimension  lines,  object  lines,  and  dotted  lines.  Care 
must  be  taken  not  to  apply  so  much  pressure  on  the  pencil  that  it  will 
cut  the  paper. 

Figure  I,  which  shows  the  proper  and  improper  sharpening  of  the 
pencil,  should  be  given  careful  examination.  A  pencil  cannot  be  prop- 
erly sharpened  with  a  dull  knife,  and  the  knife,  however  sharp,  should 
never  be  employed  for  anything  except  the  whittling  away  of  the  wood. 
Allow  about  14"  of  the  lead  to  project  from  the  wood  after  whittling, 
and  by  the  aid  of  fine  sand  paper,  or  a  fine  file,  shape  the  lead  prop- 
erly, as  shown  in  the  illustration. 

ERASERS 

Very  little  needs  to  be  said  on  the  use  of  Erasers.  Each  student 
should  be  provided  with  one  soft  red  rubber  eraser  for  the  removal  of 
pencil  lines,  one  eraser  containing  a  gritty  substance  for  removing  ink, 
and  one  cleaning  eraser  such  as  art  gum  for  removing  dirt,  finger  marks, 
etc.,  from  the  paper. 

THUMB    TACKS 

Thumb  Tacks  are  used  to  hold  or  fasten  the  paper  in  its  proper 
position  on  the  Drawing  Board.  A  tack  with  a  round  tapering  pin 
and  5/16'"  round  oval  head  is  best.  With  careful  use  half  a 


[10] 


nc.i 


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EDGE 


4  H  PENCIL.   PROPERLY      WRONG 

Srt*f?faE/VE&  roJ* 

LINE:  WO&K 


<5  H    F^NC/L    WlTM 
FfOUND    f»O//VT  FOR 
LETTER/NO, 


HUT  TO* 


n] 


dozen  tacks  should  be  sufficient.  The  tacks  should  never  be  driven  in 
with  the  T-Square  or  any  other  instrument,  but  should  be  pressed  in 
with  the  ball  of  the  thumb.  As  the  Drawing  Board  is  constructed  of 
soft  pine,  this  operation  is  not  at  all  difficult. 

Care  should  be  exercised  in  the  extraction  of  thumb  taeks.  If  they 
are  pried  out  by  placing  an  instrument  under  the  edge,  the  stem  is  very 
apt  to  bend,  and  after  a  few  such  operations  it  will  break  off.  The 
simplest  way  to  extract  a  thumb  tack  is  to  grasp  the  edge  of  the  head  with 
the  nails  of  the  thumb  and  middle  finger,  at  the  same  time  twisting  the 
tack  to  the  right  and  left.  It  will  be  found  that  this  loosens  it  so  that 
it  can  easily  be  pulled  straight  out,  since  the  action  applies  no  leverage 
or  side  motion.  This  method  greatly  increases  the  life  of  the  tack. 

INK 

It  is  advisable  not  to  purchase  the  drawing  ink  until  the  time  ar- 
rives for  ink  work  to  be  taken  up,  for  ink,  unless  it  is  in  a  perfectly  air- 
tight bottle.,  evaporates  quickly.  A  black  water-proof  drawing  ink 
of  any  standard  make  will  answer. 

PENS 

A  fine-pointed  steel  pen  such  as  the  Gillott  No.  303  or  its  equivalent 
must  be  used  for  arrow  points,  figures,  etc.  The  pen  must  be  wiped 
thoroughly  after  using  and  before  the  ink  dries,  or  its  life  will  be  of 
short  duration. 

THE   PROTRACTOR 

The  Protractor  is  an  instrument  used  for  measuring  and  laying  off 
angles  (Fig.  II,  p.  13).  It  is  semicircular  in  shape  and  is  usually  grad- 
uated in  degrees  and  half  degrees.  In  laying  off  or  locating  an  angle,  the 
point  on  the  Protractor  representing  the  horizontal  center  (A)  is  to  be 
placed  on  the  vertex  point  of  the  angle,  or  the  place  where  the  vertex 
of  the  angle  is  to  appear.  The  horizontal  line  (B)  on  the  Protractor 
should  coincide  with  the  base  line  of  the  angle  (C)  as  shown  in  the  illus- 
tration. The  number  of  degrees  to  be  found  or  located  can  then  be  read 
off  on  the  semicircular  or  graduated  edge  (D)  of  the  Protractor. 


[12] 


20' 


ric.  n 


PROTRACTOR 


[13] 


THE   IRREGULAR   CURVE 

The  Irregular  or  French  Curve  (A,  Fig.  Ill)  is  an  instrument 
used  for  the  construction  of  lines  which  are  not  straight  but  which 
cannot  be  drawn  with  a  compass.  In  the  construction  of  such  lines, 
points  should  be  located  in  the  direct  path  of  the  line  1,  2,  3,  4, 
etc.  (Fig.  III).  After  these  points  have  been  located  the  curved  line 
must  be  drawn,  a  little  at  a  time.  In  this  process  the  edge  of  the  Ir- 
regular Curve  (A)  is  used  as  a  guide.  To  insure  perfect  results  the 
edge  of  the  Irregular  Curve  must  pass  through  at  least  three  points  at 
each  setting  and  as  many  more  points  as  possible.  If  the  curve  to  be 
constructed  is  of  considerable  length,  adjust  the  Irregular  Curve  so  that 
the  edge  of  it  will  pass  gracefully  through  three  or  four  points,  and  draw 
this  section ;  then,  using  the  last  two  points  in  the  section  just  drawn  as 
a  guide,  readjust  the  Irregular  Curve  so  that  it  will  pass  through  these 
last  two  points  and  as  many  new  points  as  possible.  Continue  this  process 
until  the  required  curve  is  completed. 

Both  the  Protractor  and  the  Irregular  Curve  should  be  made  of  a 
transparent  material  such  as  is  used  for  the  Triangles. 

THE   RULER 

The  Ruler  best  adapted  to  Mechanical  Drawing  work  is  the  beveled 
edge  type,  12"  in  length  and  graduated  to  sixteenths  (B,  Fig.  IV). 
The  Ruler  is  used  only  to  determine  distances.  It  is  not  intended  to  be 
used  as  a  guide  for  drawing  lines.  The  T-Square  and  the  Triangles 
are  for  this  purpose,  as  will  be  explained  later. 


[14] 


r/c.  m 


HUTTON 


[15] 


THE    SCALE    RULE    (A,    FIG.    IV  ) 

The  principle  involved  in  the  Scale  Rule  is  very  puzzling  to  the 
beginner,  but  he  will  see  clearly  its  use  and  advantage  by  giving 
strict  attention  to  the  following  explanation. 

Let  us  suppose  that  we  are  to  make  the  drawing  of  a  certain  object, 
the  length  of  which  we  will  say  is  nearly  twice  that  of  the  paper  on 
which  it  is  to  be  drawn.  How  can  we  accomplish  this?  It  should  occur 
to  us  at  once  that  the  object  must  be  drawn  half  its  actual  size.  Let 
us  analyze  what  this  means.  We  have  practically,  as  far  as  this  indi- 
vidual drawing  is  concerned,  reduced  the  size  of  our  rule  just  one- 
half.  In  other  words  a  6"  measurement  on  our  half-size  drawing 
equals  a  1'  measurement  on  the  object  being  drawn.  Our  drawing, 
then,  if  made  to  a  scale  of  6"  equals  12",  or  I'  (commonly  called 
scale  6"  -  12"),  will  be  one-half  size. 

Suppose  that  we  are  required  to  make  a  drawing  of  a  building  100  feet 
in  length,  and  that  we  have  a  piece  of  paper  just  30  inches  long  on 
which  to  represent  or  draw  this  building.  If  we  were  to  draw  it  full 
size  it  would  require  a  paper  100  feet  in  length.  If  we  were  to  draw  it 
half  size  it  would  require  a  paper  50  feet  in  length.  So,  knowing  that 
the  size  of  our  drawing  must  be  within  the  limit  of  30  inches,  we  must 
look  for  a  scale  on  our  Scale  Rule  that  will  meet  the  requirements.  Let  us 
say  we  will  make  our  drawing  to  a  scale  of  "y±"  equals  1'."  It  can 
be  readily  seen  that,  drawn  according  to  this  scale,  our  building  will 
be  just  25"  long  on  paper.  On  your  triangular  Scale  Rule  you  will 
find  spaces  as  follows: 

3      inches  long  representing  1  foot. 


I/  »  »  »  » 

/4 

3/16 
1  /       »         »  »  » 

78 

3/32     " 

You  will  find,  also,  a  regular  12"  Rule  divided  in  inches,  halves, 
quarters,  eighths,  and  sixteenths. 


[16] 


XVA 


0) 


*     -3 


*  v 


*? 


(A 

5 
* 


[17] 


Now  notice  the  3"  scale  (C,  Fig.  IV)  and  you  will  sec  that  it  is 
divided  into  twelve  equal  parts;  therefore  at  a  scale  of  3"  to  the  foot, 
each  one  of  these  divisions  equals  1".  The  1"  space  is  divided  in  the 
center  by  a  long  line ;  this  makes  two  shorter  spaces  eacli  repre- 
senting the  half  of  V,  or  */•>".  The  1/2"  space  is  divided  by  a  line  not 
so  long,  which  makes  two  still  shorter  spaces  each  representing  the 
half  of  !/£",  or  14".  This  14"  space  is  divided  by  a  line  shorter  than 
the  rest  and  represents  a  distance  of  %". 

It  will  be  seen,  therefore,  that  the  3"  Space  (C,  Fig.  IV)  thus 
divided  is  nothing  but  a  miniature  12"  rule  in  exact  proportion  in 
.every  way.  So  it  is  with  every  scale  shown  on  the  Scale  Rule.  They 
are  all  miniature  12"  rules,  but  they  are  not  all  divided  to  %",  for 
if  they  were  the  divisions  would  be  so  small  they  could  not  be  read. 
Look  at  the  %"  scale  and  see  how  small  the  divisions  are.  Each 
small  division  on  this  scale  represents  1  inch. 

Now  let  us  turn  our  rule  so  that  we  again  have  the  3"  scale 
before  us.  From  the  3"  scale,  reading  to  the  left,  you  will  find 
in  the  groove  the  figures,  in  their  order — 0,  1,  2,  etc. — which  mean  that 
the  distance  from  the  0  to  the  figure  2  represents  2'  on  the  scale  of 
"3"  equals  1'."  Suppose  we  wish  to  step  off  a  distance  of  2'  and  6" 
on  this  scale.  From  the  0  to  the  right  in  their  order  and  in  the  groove 
you  will  see  the  figures  0,  3,  6,  9.  So  the  distance  from  the  figure  2 
at  the  left  of  the  0  in  the  groove  to  the  figure  6  at  the  right  of  the  0 
in  the  groove  will  be  an  exact  measurement  representing  2',  6"  at  a 
scale  of  "3"  equals  IV 

By  dividing  12"  by  3"  we  find  that  in  drawing  the  object  to  a 
scale  "of  3"  equals  1',''  we  will  have  the  drawing  when  finished, 
exactly  ^  size.  Drawing  an  object  14  size  without  the  use  of  a 
Scale  Rule  would  require  considerable  time  in  figuring  for  each 
dimension.  Moreover,  the  possibility  of  making  a  mistake  would  always 
be  on .  the  draftsman 's  mind,  which  would  take  his  attention  from  his 
work.  Later,  as  a  matter  of  practice,  so  that  you  will  become  familiar 
with  the  Scale  Rule  in  all  its  details,  you  will  be  required  to  draw  a 
series  of  lines  all  of  different  lengths  and  to  different  scales. 

When  you  arrive  at  the  part  of  the  work  which  requires  this,  review 
very  carefully  all  that  has  been  said  about  the  Scale  Rule.  In  this  re- 
view keep  the  Rule  itself  constantly  before  you  for  reference. 


[18] 


DRAWING    BOARD 

The  first  tool  with  which  we  come  in  contact  is  a  Drawing  Board.  The 
kind  and  size  of  board  to  purchase  depend  largely  upon  the  future  use 
to  which  you  intend  to  put  it.  If  you  contemplate  High  School  or 
University,  a  board  of  considerable  size  would  be  advisable.  If  a  board 
is  not  furnished  by  the  school,  ask  the  advice  of  your  teacher  as  regards 
the  size.  Any  board  chosen  should  be  constructed  of  select  dry  white 
pine  properly  reinforced  to  prevent  warping. 

DRAWING    SETS 

A  Drawing  Set  containing  the  variety  of  tools  specified  in  the  equip- 
ment list  can  be  purchased  at  various  prices  according  to  the  quality  and 
amount  of  material  and  workmanship  expended  on  them.  A  medium 
priced  set  will,  with  proper  care,  last  for  a  number  of  years; 

A  set  constructed  with  all  center  points  removable  is,  when  con- 
sidered from  a  standpoint  of  accuracy  and  durability,  advisable.  Any 
set  purchased  must  be  kept  bright  and  clean.  Ink  must  never  be  al- 
lowed to  dry  in  the  pens  as  this  corrodes  the  metal  and  causes  a  rough- 
ness which  naturally  interferes  with  the  proper  flow  of  the  ink.  When 
the  pens  are  not  in  use  be  sure  that  the  adjusting  screw  is  set  so  that 
the  pen  points  are  open.  If  the  pens  are  laid  away  with  adjusting  screw 
run  up  tight  so  as  to  place  considerable  tension  on  the  pen  blades  it  will 
be  found  in  time  that  the  natural  spring  of  the  blades  will  be  lost  and 
that  the  pen  will  be  rendered  useless. 

The  individual  use  of  the  drawing  instruments  will  be  taken  up  as 
the  use  for  them  arises  in  the  different  exercises,  problems,  etc. 


[19] 


T-SQUARE 

The  T-Square  consists  of  head  and  blade  (see  Fig.  V,  p.  21).  The 
inside  edge  of  the  head  and  both  edges  of  the  blade  must  be  perfectly 
straight  and  free  from  nicks,  and  the  head  and  blade  must  be  set  perma- 
nently at  an  angle  of  90  degrees  to  each  other.  The  blade  of  the 
T-Square  should  not  be  shorter  than  the  length  of  the  Drawing  Board. 

TRIANGLES 

The  Triangles  (see  Fig.  V)  are  two  in  number,  one  of  which  is  com- 
monly called  a  45-degree  and  the  other  a  30-degree  Triangle.  These 
tools  are,  as  the  word  triangle  implies,  three-cornered.  The  30-degree 
Triangle  has  one  corner  which  measures  30  degrees,  or  the  twelfth 
part  of  a  circle,  one  60  degrees,  or  the  sixth  part  of  a  circle,  and  one 
90  degrees,  or  the  fourth  part  of  a  circle.  The  45-degree  Triangle  has 
two  corners,  each  of  which  measures  45  degrees  or  the  eighth  part  of 
a  circle,  and  one  which  measures  90  degrees. 

Both  Triangles  should  be  made  of  a  transparent  material  such  as 
celluloid.  They  are  to  be  used  in  connection  with  the  T-Square. 

HORIZONTAL    AND    VERTICAL    LINES 

All  horizontal  lines  (see  Fig.  V)  are  drawn  by  using  the  upper 
edge  of  the  T-Square  blade  as  a  guide  for  the  pencil.  All  perpendicular 
or  vertical  lines  are  drawn  by  using  an  edge  of  one  of  the  Triangles 
as  a  guide  for  the  pencil.  In  order  to  get  proper  results  and  to  have 
all  horizontal  lines  parallel,  the  head  of  the  T-Square  must  be  used  in 
direct  contact  with  the  left  end  of  the  Drawing  Board.  Much  care 
must  be  exercised  in  this,  for  if  the  full  length  of  the  inside  edge  of  the 
T-Square  head  is  not  firmly  pressed  against  the  left  end  of  the  board, 
corresponding  lines  on  the  drawing  will  not  be  parallel.  The  top  edge 
of  the  T-Square  blade  is  used  also  as  a  base  for  the  Triangles.  The 
edge  of  the  Triangle  perpendicular  to  the  T-Square  blade  is  used  as  a 
guide  for  the  pencil  in  drawing  vertical  lines.  Therefore,  it  should  be 
readily  seen  that  the  foundation  guide  for  vertical  lines  as  well  as  hori- 
zontal lines  is  the  T-Square  head  in  contact  with  the  end  of  the  Draw- 
ing Board  (see  Fig.  V).  This  is  a  fundamental  principle  which  must  be 
mastered.  It  can  be  done  quickly  if  the  directions  given  are  carefully 
followed. 


[20] 


[21] 


LINES  TO  USE 

Examine  carefully  the  several  different  kinds  of  lines  used  (Fig. 
VI).  When  inked  in,  the  construction,  the  dimension,  center,  and  dotted 
lines  should  be  much  lighter  than  the  object  line,  yet  heavy  enough  to 
be  distinct.  The  dimension  line  consists  of  two  long  dashes  with  space 
between  them  for  the  dimension,  or  distance  between  arrow  points,  as 
shown.  All  arrow  points  must  be  small,  narrow,  and  solid  black.  The 
wide,  uneven  arrow  point  is  to  be  avoided.  Points  of  the  arrows  must 
touch  the  lines,  the  distance  between  which  is  represented  by  the  figure. 
To  extend  the  arrow  points  through  these  lines  or  to  place  them  away 
from  the  inside  of  these  lines  is  absolutely  incorrect. 

The  center  line  is  constructed  the  same  as  the  dimension  line  with  the 
exception  that  two  short  dashes  are  placed  in  each  space  between  the  long 
dashes.  Center  lines  are  used,  as  the  name  implies,  to  represent  centers 
of  objects  or  parts  of  objects.  At  times  the  crossing  of  two  center  lines 
represents  the  location  of  centers  of  circles  or  parts  of  circles.  The 
dotted  or  hidden  line  as  shown  is  used  for  representing  that  part  of  an 
object  which  lies  behind  the  surface.  When  inked  the  object  line  must 
correspond  in  thickness  with  the  object  line  shown  in  Figure  VI. 


[22] 


nc.m 


CoNSTFlUC  TION    L  IN£S 


CENTE, 


'/?        L  FNE5 


DOTTED  Of?  HWDCN  LINES 


DIMENSION    LIMES 


OBJECT   LINES 


LINES 


[23] 


LETTERING 

After  the  proper  drill  on  the  obstruction  of  different  kinds  of 
lines  has  been  had,  it  will  be  found  easy  to  construct  guide  lines  for 
letters  as  shown  in  the  examples  of  alphabets  and  illustrated  as  con- 
struction lines  in  Figure  VII,  p.  25.  If  the  illustrations  are  studied 
attentively  little  need  be  said  on  the  subject.  Notice  carefully  the  differ- 
ent steps  taken  in  constructing  the  letters  that  make  up  the  word  Chicago 
(Fig.  VII).  Draw  horizontal  construction  lines  representing  top,  cen- 
ter, and  bottom  of  letters.  Space  off  all  letters  to  be  drawn  (A,  Fig. 
VII)  with  the  Bow  Dividers.  Draw  your  slant  lines  mechanically,  as 
illustrated  in  Figure  I,  page  26,  and  mark  each  space  with  the  letter  it 
is  to  develop  into,  as  showTn  at  B  (Fig.  VII).  Brighten  all  horizontal 
lines  for  letters  (C).  Brighten  all  vertical  lines  for  letters  (D).  Draw 
in  and  brighten  all  other  lines  as  the  bar  of  the  G,  the  side  of  the  A,  etc. 
(E).  Erase  all  construction  lines  so  that  the  word  will  be  neat  and  clear 
as  at  F.  Some  letters,  on  account  of  their  peculiar  shape,  require  a 
little  diversion  from  the  ordinary  rule,  as  A,  B,  K,  M,  V,  W,  etc.,  shown 
in  Plate,  page  26.  Note  their  peculiarities  and  construct  them  accord- 
ingly. All  mechanical  lettering  is  to  be  done  as  just  described. 

In  the  small  letters,  which  are  made  freehand,  draw  first  the  guide 
lines,  top  and  bottom.  The  distances  between  the  guide  lines  should  corre- 
spond with  those  shown  on  Plate,  page  26. 

Considerable  practice  is  required  before  one  can  letter  properly,  either 
mechanically  or  freehand.  The  letters  must  all  be  the  same  in  height 
and  in  case  of  slant  letter  the  slant  should  be  uniform.  As  an  aid  in 
making  all  freehand  letters  the  same  slant,  place  your  arm  so  that  its 
slant  relation  with  the  guide  lines  is  the  same  as  the  desired  slant  of  the 
letter.  Make  sure  that  all  letters  touch  both  top  and  bottom  guide 
lines  and  construct  them  so  that  they  will  be  a  little  wider  than  they 
are  high.  Always  keep  an  even  space  between  letters  and  double  this 
space  between  words. 

All  lettering  given  is  of  a  simple  type.  Good  results  will  be  easily 
obtained  through  practice  if  directions  are  followed.  As  good  lettering 
is  essential  to  the  neat  appearance  of  a  drawing  there  should  be  practice 
in  lettering  whenever  an  opportunity  presents  itself.  It  may  be  well,  un- 
der the  guidance  of  the  instructor,  to  prepare  a  formal  sheet  of  letters. 

NOTE.  If  it  is  so  desired,  a  special  angle  for  lettering  only  can  be 
constructed  as  shown  in  Figure  II,  Plate,  page  26. 


[24] 


no.  JZE 


/     //     ///     //     //     //     / 

/    //    ///    //    //    //  7" 


c  "ill  fji  'ii'n 


I    II    777/7 


C    ,  ,      A   ,  .     C,.     O 


i  II  !  II!  It  11 

I  II  in       I   I 

I!  In    II   if  it 


c// "/// c 


l  il 


t  I  nil!  II  I 


CH/C/7CO 


[25] 


g 


? 

§ 


8 


DRILL  IN  USE  OF  INSTRUMENTS 

Before  attempting  any  of  the  exercises  a  short  drill  on  the  proper 
method  of  fastening  a  sheet  of  drawing  paper  to  the  drawing  board  by 
means  of  thumb  tacks  will  be  necessary.  After  the  pencils  have  passed 
the  inspection  of  your  teacher  proceed  to  fasten  a  piece  of  paper,  size  9" 
X  12"  on  your  Drawing  Board  by  the  aid  of  thumb  tacks.  Observe 
strictly  the  following  method,  as  it  is  practical,  simple,  easy,  and  correct. 

Place  the  paper,  a  good  quality  for  drawing,  in  the  center  of  the 
Drawing  Board  and  with  the  ball  of  the  thumb  press  into  place  one 
thumb  tack  in  the  upper  right  hand  corner  of  the  paper.  As  there  is 
but  one  thumb  tack  in  place  the  paper  can  be  easily  moved  up  and 
down  with  that  corner  of  the  paper  the  thumb  tack  has  pierced  acting 
as  a  pivot.  Now  place  the  T-Square  in  position  as  in  Figure  V,  page  21, 
with  the  head  of  the  T-Square  to  the  left,  and  the  inside  of  the  head  held 
directly  and  firmly  against  the  end  of  the  Drawing  Board.  Keeping 
the  head  in  this  position  move  the  T-Square  up  with  the  left  hand  until 
it  is  in  line  with  the  corner  of  the  drawing  paper  through  which  the 
thumb  tack  has  been  passed.  With  that  corner  of  the  paper  acting  as 
a  pivot,  as  previously  explained,  move  the  paper  up  or  down,  as  the 
case  may  be,  until  the  top  edge  of  the  drawing  paper  is  in  perfect  line 
with  the  top  edge  of  the  T-Square. 

Hold  the  paper  in  this  position  with  the  hand  and  press  into  place 
one  more  tack  in  the  upper  left  hand  corner.  In  pressing  the  tack  into 
place,  care  must  be  taken  that  it  travels  perpendicularly  to  the  surface 
of  the  Drawing  Board,  and  that  the  under  part  of  the  tack  head  comes, 
in  direct  contact  with  the  paper  at  all  points.  The  contact  of  the  under 
surface  of  the  tack  head  with  the  paper,  when  the  tack  is  pressed  firmly 
against  the  board,  gives  far  more  holding  power  than  the  pin  of  the  tack 
passing  through  the  paper.  If  desired,  additional  tacks  may  be  placed  in 
both  lower  corners,  but  for  a  paper  of  this  size  it  is  not  necessary. 
If  tacks  are  placed  in  the  lower  corners  of  the  paper  it  will  cause  some 
inconvenience  when  drawing  in  that  immediate  section,  as  a  rocking 
motion  of  the  blade  is  unavoidable  when  the  T-Square  is  in  position 
and  directly  over  the  tacks.  Then,  too,  the  T-Square  blade  is  apt  to 
become  nicked  or  marred  if  it  comes  constantly  in  contact  with  the 
edge  of  the  tack. 


[27] 


EXERCISES.  In  selecting  the  exercises  much  care  has  been  taken  to  have  a  series 
that  not  only  embraces  the  proper  use  of  all  drawing  tools  but  at  the  same  time 
presents  a  pleasing  appearance  and  an  interesting  set  of  problems. 

It  will  be  found  that  these  exercises  bring  together  and  develop  the  best  facul- 
ties of  the  brain,  the  hand,  and  the  eye,  and  promote  neatness  and  accuracy.  They 
impress  on  the  mind  of  the  student  the  absolute  necessity  of  light  construction  lines. 
Without  the  proper  and  accurate  use  of  the  Ruler,  T-Square,  Triangles,  etc.,  and  with- 
out pencils  sharpened  in  the  proper  manner,  they  cannot  be  executed.  Each  exercise 
should  be  worked  through  as  described  below. 


EXERCISE  I— LAY  OUT  OF  SHEET 

Study  Figure  V,  page  21,  carefully.  When  the  paper  has  been  prop- 
erly fastened  to  the  Drawing  Board  proceed  to  construct  the  border 
lines.  These  consist  of  a  horizontal  line  at  the  top  and  bottom  and  a 
vertical  line  on  each  side  (Ex.  I,  page  29).  Each  of  these  lines  should 
be  ^2"  from  the  edge  of  the  paper.  In  drawing  each  horizontal  line, 
measure  the  }£"  distance  in  from  the  edge  of  the  paper  in  one  place 
only.  After  you  are  sure  that  the  T-Square  is  held  in  the  proper 
position,  draw  the  line  through  this  point,  with  the  blade  of  the 
T-Square  as  a  guide. 

The  vertical  lines  also  are  to  be  drawn  with  but  one  measurement 
for  each.  Use  one  90-degree  edge  of  the  Triangle  as  a  guide  for  the 
line;  let  the  other  rest  on  the  T-Square.  Make  sure,  as  before,  that 
the  T-Square  is  held  in  the  proper  position.  (Examine  carefully 
Fig.  V,  page  21.) 

These  lines  must  be  very  faint  construction  lines,  as  it  is  required 
that  they  be  gone  over  or  brightened  in  the  spaces  between  the  inter- 
section or  crossing  of  horizontal  and  vertical  lines.  The  short  construc- 
tion lines  which  remain  at  each  corner  (Ex.  I,  A)  outside  of  these  inter- 
secting points,  will  later  be  erased  so  as  to  leave  a  perfect  rectangle.  If 
it  is  found  that  the  paper  is  not  exactly  square  at  the  corners,  the  sur- 
plus can  be  trimmed  off  when  the  plate  is  finished. 


[28] 


EDGE:   or 


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[29] 


In  the  rectangle  formed  by  the  border  lines  will  be  constructed  four 
smaller  rectangles — I,  J,  K,  and  L — of  the  same  size,  each  of  which  has 
a  space  (D)  of  y2"  around  its  edges.  The  first  step  will  be  to  locate 
construction  lines  half  way  between  the  border  lines  in  both  a  horizontal 
and  vertical  direction.  On  each  side  of  each  of  these  construction  lines 
step  off  a  distance  of  14"  (B).  This  can  best  be  done  by  adjusting  the 
points  of  the  Bow  Dividers  to  an  exact  distance  of  y4".  Place  one  point 
of  the  Dividers  on  the  line  and  mark  the  required  distance  on  each  side 
of  it  with  the  other  point.  Draw  in  your  horizontal  and  vertical  con- 
struction lines  in  the  same  manner  as  the  border  lines  were  drawn. 

Set  the  points  of  the  Bow  Dividers  to  a  distance  of  y/'  and  step 
off  this  distance  on  the  inside  of  each  border  line  as  at  D.  After 
passing  construction  lines  through  the  points  thus  located,  brighten  up 
the  required  rectangles — I,  J,  K,  and  L — and  erase  all  projecting  con- 
struction lines.  You  now  have  four  perfect  rectangles  of  the  same  size 
and  with  an  equal  space  of  V.,"  around  their  edges.  Exercise  I  is 
shown  with  construction  lines  erased  from  the  lower  half  of  the  paper. 
Study  this  drawing  carefully.  Read  the  above  again  and  follow  the  dif- 
ferent steps  on  the  drawing  as  you  read. 

You  are  now  ready  to  fill  the  four  rectangles  of  Exercise  I  with 
dimensions,  center,  dotted,  and  object  lines.  Before  attempting  this, 
however,  plan  carefully  the  distance  apart  you  wish  the  lines.  Fill  one 
rectangle  with  dimension,  one  with  center,  one  with  dotted,  and  one  with 
object  lines.  In  doing  this  draw  some  horizontally,  some  vertically,  and 
some  in  a  diagonal  direction.  Use  a  different  angle  for  each  rectangle. 
Care  must  be  taken  that  all  lines  are  as  nearly  perfect  as  possible,  and 
uniformly  spaced. 

If  your  plate  is  not  satisfactory,  redraw  it,  write  your  name,  etc., 
on  the  back,  and  lay  it  carefully  away.* 

After  proficiency  in  making  letters  and  figures  has  been  obtained,  the 
first  exercise  can  be  lettered  Exercise  I  as  shown,  and  with  name,  age, 
grade,  school,  etc.,  between  lower  border  line  and  edge  of  paper.  Never 
letter  directly  on  the  edge  of  paper  or  on  border  line. 


*  \  portfolio  will  be  found  of  great  convenience  for  preserving  drawings.  One  can  be 
made  from  two  pieces  of  cardboard  each  about  12"xl6".  These  should  be  hinged  at  one  end 
with  ribbons,  threaded  through  holes  punched  in  the  proper  places,  and  tied. 


[30] 


EXERCISE  II— BASKET  WEAVE 

Before  commencing  the  construction  as  shown  in  Exercise  II  it  will 
be  necessary  to  prepare  a  9"  X  12"  sheet  of  drawing  paper  the  same 
as  in  Exercise  I.  This  time  the  rectangles  are  to  be  filled  with  the 
basket  weave  as  shown  in  Exercise  II. 

Construct  the  diagonal  weave  (Fig.  I,  Ex.  II)  in  the  upper  left  hand 
rectangle  (I,  Ex.  I)  as  follows: 

Adjust  the  points  of  the  Bow  Dividers  so  that  they  have  a  spread  of 
exactly  y4".  A  good  test  for  their  accuracy  is  to  set  one  point  on  a 
!/4"  graduation  of  the  Rule,  step  off  a  distance  of  2"  or  3",  y4"  at  a 
time,  always  keeping  one  point  of  the  Dividers  on  the  Rule.  If  the 
Dividers  were  set  accurately  the  points  will  at  the  end  of  this  distance 
rest  exactly  on  y±"  graduations.. 

When  you  have  your  Dividers  set  with  absolute  accuracy  place  one 
point  of  the  Dividers  on  the  corner  (E,  Ex.  I)  of  the  upper  left  hand 
rectangle,  (I).  Then  proceed  to  the  right  and  divide  the  top  of  the 
rectangle  into  as  many  %"  spaces  as  possible.  Make  sure  in  this 
operation  that  the  points  of  the  Dividers  at  all  times  rest  exactly  on, 
and  not  above  or  below,  the  line.  Again  set  one  point  of  the  Dividers 
at  the  same  starting  place,  E ;  proceeding  downward,  divide  the  end  of 
the  rectangle  in  a  similar  manner. 

All  the  points  necessary  for  the  spacing  of  construction  lines  being 
located,  proceed  to  draw  them  as  in  Figure  I,  Exercise  II.  Use  the 
diagonal  edge  of  the  45-degree  Triangle  as  a  guide  as  shown  in  the 
lower  right  hand  corner  of  Figure  V,  page  21.  In  this  drawing,  however, 
the  construction  lines  to  be  drawn  first  must  slant  in  the  opposite 
direction,  or  in  the  direction  shown  at  A,  Figure  I,  Exercise  II.  Proceed 
to  the  left,  drawing  light  construction  lines  through  each  point  located  on 
the  end  as  well  as  on  the  top  line  of  the  rectangle.  With  the  T-Square 
in  same  position  reverse  or  turn  over  the  Triangle  and  in  the  same  man- 
ner draw  construction  lines  in  the  opposite  direction,  as  in  B,  Figure  I, 
Exercise  II.  When  this  is  completed  it  will  be  seen  that  the  rectangle 
is  divided  into  a  number  of  small  squares  and  parts  of  squares.  If  the 
work  has  been  properly  executed  the  construction  lines  will  be  so  faint 
that  they  can  hardly  be  detected — fainter  by  far  than  the  construction 
lines  shown  in  Exercise  II,  Figure  I.  All  the  squares  ought  to  be 
exactly  the  same  in  size.  If  this  is  not  the  ease  the  exercise  so  far  as  it 
is  completed  should  be  redrawn,  as  good  results  are  impossible  without 
exactness. 


[32] 


EXERCISE  H 


[33] 


Proceed  in  the  following  systematic  manner  to  brighten  certain  lines 
which  form  the  over  and  under  appearance  of  tin-  weave.  At  any  point, 
as  at  C,  Figure  I,  Exercise  II,  brighten  a  pair  of  lines  three  spaces  in 
length,  Brighten  a  pair  of  lilies  at  right  angles  to  these  lines,  as  at  1). 
thus  forming  a  rectangle,  one  space  wide  and  three  spaces  long.  ( 'ontinue 
this  process  until  the  entire  space  in  the  rectangle  is  covered.  When  the 
brightening  process  is  completed  carefully  erase  all  construction  lines 
as  in  Figure  II,  Exercise  II.  This  part  of  the  plate  is  then  finished. 
Without  further  explanation  proceed  to  fill  upper  right  hand  rectangle, 
J,  Exercise  I,  in  the  same  manner,  except  that  the  size  of  divisions  is 
increased  from  14"  to  %"  in  measurement.  This  over  and  under  weave 
appearance  can  also  be  executed  with  horizontal  and  vertical  construction 
lines,  which  will  give,  when  finished,  a  horizontal  and  vertical  instead  of 
a  diagonal  appearance.  Use  exactly  the  same  process  in  the  lower  left 
hand  rectangle  (K),  and  construct  an  over  and  under  weave  of  the 
vertical  and  horizontal  type  with  14"  as  a  standard  for  spacing.  In  the 
lower  right  hand  rectangle  (L)  construct  a  vertical  and  horizontal 
weave  using  %"  as  a  standard.  After  you  have  erased  all  construction 
lines,  etc.,  print  carefully  freehand  between  two  guide  lines,  placed  ex- 
actly midway  between  border  line  and  edge  of  paper  (M,  Ex.  I)  your 
name,  age,  grade,  school,  etc.  This  completes  your  plate  (Ex.  II). 

EXERCISE   III— APPLICATION  OF  BASKET  WEAVE 

The  principle  involved  in  the  construction  of  Exercise  III  is  the  same 
as  that  of  the  square  weave,  (Ex.  II),  just  finished.  P'or  this  exercise 
use  an  entire  sheet  9"  X  12".  First  construct  the  border  lines  so  that 
you  will  have  a  rectangle  8"  X  11".  On  the  vertical  center  line  between 
the  side  border  lines  and  a  little  toward  the  bottom  of  the  paper  from 
the  center  of  the  sheet,  construct  with  T-Square  and  Triangle  a  perfect 
square  exactly  5%"  X  5%".  Divide  the  top  and  one  side  of  this  square 
into  fifteen  spaces,  each  space  exactly  %".  With  the  T-Square  and 
Triangle  as  guides  draw  in  the  horizontal  and  vertical  construction 
lines  as  shown  in  Exercise  III  in  the  top  square.  Brighten  carefully  the 
required  lines  so  as  to  bring  out  the  design  distinctly.  Erase  all  con- 
struction lines.  Above  the  design  and  in  the  center,  print  in  slant 
capitals,  EXERCISE  III.  Under  border  line  as  before  print  name,  age, 
grade,  school,  etc.  The  upper  square  in  Exercise  III  shows  the  con- 
struction. The  student  will  have  one  square  only  on  his  sheet  and  that 
will  look  like  the  bottom  square  in  Exercise  III. 


[34] 


p 


n 


n 


Q 


n 


D 


CT 


[35] 


EXERCISE  IV— CIRCULAR  WEAVE 

This  Compass  exercise  requires  a  combination  of  horizontal,  vertical, 
and  diagonal  lines  in  its  construction.  The  lines  just  mentioned  may 
be  classed  as  sub-construction  lines,  as  they  locate  the  centers  of  the 
circular  construction  lines  that  deal  directly  with  the  design  to  be  drawn. 
As  in  Exercises  II  and  III,  Exercise  IV  has  an  over  and  under  weave 
appearance.  For  this  exercise  the  entire  9"  X  12"  sheet  of  paper  will  be 
needed.  On  the  vertical  center  line  between  the  side  border  lines  and 
a  little  toward  the  bottom  of  the  paper  from  the  center  of  the  sheet,  locate 
a  point.  Examine  the  small  or  Bow  Compass  to  see  that  the  lead  is 
sharp  and  that  the  shouldered*  end  of  the  steel  center  point  is  out.  Run 
up  the  adjusting  screw  of  the  Bow  Dividers  so  that  the  lead  and  the 
shouldered  steel  points  come  nearly  in  contact  with  each  other.  Then 
adjust  these  points  so  that  they  will  be  of  the  same  length. 

Again  by  the  use  of  the  adjusting  screw  set  the  lead  and  the  steel 
points  to  an  exact  distance  of  one  inch.  After  the  Compass  is  once  set 
accurately  it  must  not  be  changed  during  the  entire  process  of  construct- 
ing or  finishing  the  exercise. 

With  the  steel  points  set  on  the  center  already  found,  draw  a  faint 
circular  construction  line  (1,  Fig.  I).  By  means  of  the  T-Square  and 
the  Triangle  draw  horizontal  and  vertical  construction  lines  A  and  B 
so  that  they  pass  exactly  through  the  center  of  the  circle  ( 1 ) . 

By  the  aid  of  the  T-Square  and  the  diagonal  edge  of  the  45-degree 
Triangle,  pass  through  the  same  center  the  two  diagonal  construction 
lines,  C  and  D.  The  circle  (1)  has  now  been  divided  into  exactly  eight 
equal  parts.  Use  as  centers  the  points  where  the  horizontal,  vertical, 
and  diagonal  construction  lines,  A,  B,  C,  and  D,  intersect  or  cross  the 
circle  (1)  and  draw  eight  more  light  construction  circles  as  2,  3,  4,  etc. 

In  the  construction  of  this  exercise  sixteen  evenly  spaced  circles 
are  necessary.  So  far  eight  of  these  have  been  located.  It  is  evident 
then  that  points  must  be  located  on  circle  1  exactly  half  way  between 
the  eight  center  points,  A,  B,  C,  D,  etc.,  already  found.  In  other 
words  we  must  bisect  the  distance  separating  these  points.  We  will 
pass  from  this  for  the  moment  and  direct  all  our  attention  to  what 
happened  while  drawing  the  eight  circles  2,  3,  4,  5,  6,  etc.  It  will  be 
readily  seen  that  these  eight  circles  intersect  or  cross  each  other  as  at 
point  E.  Draw  a  light  construction  line  (F)  so  that  it  will  pass  through 


*  The  shouldered  end  should  be  used  for  this  purpose  because  it  is  not  so  likely  to  wear 
a  hole  in  the  paper. 


[36] 


EXERCISE:  w 


nc.  i 


r/c.n 


[37] 


the  center  of  circle  1,  and  also  through  the  intersecting  point  E.  Exam- 
ine the  work  carefully  and  see  if  the  distance  A-C  on  circle  1  lias  not 
unknowingly  and  automatically  been  bisected  by  the  line  F  just  drawn. 

In  the  same  manner  bisect  the  other  distances.  A-l).  D-B,  B-C,  etc., 
and  draw  in  the  remaining  eight  circles,  using  the  points  just  located  on 
circle  1  as  centers. 

Brighten  the  required  lines,  erase  all  construction  lines,  and  letter 
your  plate  properly.  Exercise  IV  will  then  be  completed.  In  Figure  II, 
of  Exercise  IV,  the  completed  design  with  construction  lines  erased  is 
shown. 

EXERCISE  V— STRAIGHT  LINES  TANGENT  TO  ARCS  OF 

CIRCLES 

It  is  sometimes  very  difficult  for  the  beginner  to  locate  the  exact 
center  to  be  used  in  drawing  a  circle  or  semicircle.  Especially  is  this 
the  case  when  circles  and  semicircles  are  drawn  in  combination  with  and 
tangent  to  straight  lines.  The  construction  of  preceding  exercises,  how- 
ever, should  prepare  one  to  draw  the  different  figures  in  Exercise  V,  all 
of  which  are  used  in  problems  to  follow. 

Figure  I,  Exercise  V,  shows  the  connection  of  two  parallel  lines  by  a 
combination  of  quarter  circles.  Draw  vertical  line  A  through  the  left 
extremity  of  line  B.  Extend  line  B  to  the  left,  and  from  the  point  C 
where  lines  A  and  B  cross  or  intersect,  measure  off  a  distance  (E)  equal 
to  the  perpendicular  distance  between  lines  B  and  D.  Draw  vertical 
line  F  through  point  E,  and  horizontal  line  G  parallel  to,  and  in  the 
center  of  the  space  separating  parallel  lines,  B  and  D.  It  will  be  found 
that  the  exact  centers  of  the  circles  to  be  drawn  are  the  intersecting  points 
of  lines  A  and  G,  and  F  and  G. 

In  Figure  II  is  shown  the  proper  method  of  locating  the  center  of 
a  circle  to  be  used  in  rounding  either  the  inside  or  outside  of  a  corner. 

With  the  Compass  points  set  at  the  required  radius,  place  the  steel 
point  in  the  corner  marked  A,  and  draw  an  arc  or  portion  of  a  circle 
crossing  lines  B  and  C  at  points  D  and  E.  With  points  D  and  E  as  cen- 
ters draw  arcs  or  circles  G  and  F.  The  point  where  arcs  F  and  G  cross 
or  intersect  will  be  the  exact  center  from  which  to  draw  the  required 
circle  H. 

Figure  III  is  a  combination  of  horizontal  lines  and  semicircles.  The 
location  of  all  centers  can  be  easily  determined  with  but  very  little  con- 
struction. A  figure  similar  to  this  should  now  be  possible  of  construction 
without  further  explanation. 


[38] 


EXERCISE  Y 


nc.r 


nc.  n 


nc.  in 


B 


[391 


EXERCISE  VI— ARC  TANGENTS 

This  exercise  can  be  constructed  completely  with  the  use  of  but  one 
construction  line — a  light  vertical  line  passing  through  the  center  of  all 
circles  and  semicircles.  Draw  in  the  border  line  the  same  as  in  Exercise 
IV.  On  the  vertical  center  line  of  the  sheet  and  toward  the  bottom  draw 
a  faint  vertical  line  five  or  six  inches  in  length.  Set  the  Bow  Dividers  to 
exactly  %"  and  test  for  accuracy  as  explained  in  Exercise  II.  Step 
off  on  the  vertical  line  thirteen  points,  commencing  at  the  bottom. 

With  the  Bow  Compass  in  proper  condition  (as  explained  in  Ex. 
IV,  p.  36.)  place  the  steel  point  on  2  of  Exercise  VI,  and  adjust  the 
Compass  so  that  the  lead  will  exactly  touch  points  1  and  3.  Draw  semi- 
circle A,  and  without  readjusting,  place  steel  point  of  the  Compass  on 
point  12,  and  draw  semicircle  A'. 

Place  steel  point  of  Compass  on  point  3,  adjust  the  Compass  so  that 
the  lead  will  exactly  touch  point  5  and  draw  semicircle  B.  Without 
readjusting  the  Compass,  place  the  steel  point  on  point  11  and  draw 
semicircle  B'. 

Repeat  this  process,  using  points  4  and  10  for  drawing  semicircles 
C  and  C',  points  5  and  9  for  drawing  D  and  D',  points  6  and  8  for 
drawing  E  and  E',  and  point  7  for  drawing  circles  F  and  G. 

After  you  have  lettered  the  plate  properly  and  erased  the  construc- 
tion lines,  Exercise  VI  will  be  completed. 


[40] 


EXERCISE    E7 


[41] 


PEG  JECTION  DRAWING 


[43] 


PROJECTION  I— CUBE 

NOTE. — The  problem  of  drawing  three  mechanical  views  of  a  cube 
with  but  one  measurement  taken  is  given  not  only  as  a  quick  way  of 
locating  points,  but  also  to  impress  on  the  mind  of  the  student  the  fact 
that  the  top  view  must  alwaj^s  be  in  line  with  the  front  view  and  directly 
above  it,  and  that  a  side  view  must  always  be  in  line  with  the  front 
view  and  directly  to  the  side  of  it. 

A  level  surface  such  as  the  top  of  the  Drawing  Board  or  the  surface 
of  the  drawing  paper  when  tacked  to  the  Drawing  Board  is  commonly 
called  a  plane. 

The  Projection  Drawing  of  an  object  is  a  combination  of  views  rep- 
resenting the  same  object  from  different  points  of  view.  These  repre- 
sentation drawings  are  commonly  called  Views,  as  front  view,  side  view, 
and  top  view,  and  all  are  drawn  on  the  one  horizontal  plane — the  sheet 
of  drawing  paper. 

The  first  problem  in  projections  will  be  the  drawing  of  the  different 
views  of  a  cube — an  object  which  has  six  equal  sides,  faces,  or  surfaces. 

If  for  some  purpose  a  cube  of  wood  or  metal  was  needed,  and  a 
drawing  of  this  cube  was  to  be  made,  two  views  showing  either  the  front 
and  side,  or  the  front  and  top,  would  be  sufficient,  as  these  views  would 
give  the  length,  width,  and  thickness.  The  drawing  of  a  third  view 
would  not  be  necessary,  but  as  a  principle  of  Mechanical  Drawing  is 
involved  that  is  very  important  to  the  beginner,  the  three  views,  front, 
side,  and  top  will  be  required  in  this  drawing. 

To  represent  a  front  view  of  a  2"  cube,  draw  a  square  measuring 
2"  on  each  side.  Draw  the  side  view  of  the  cube  directly  to  one  side 
and  in  line  with  the  front  view.  This  also  will  be  found  to  be  a  square, 
each  side  of  which  measures  2". 

To  represent  a  top  view  of  a  cube,  proceed  as  in  drawing  the  side  or 
front  view ;  that  is,  draw  a  square  directly  in  line  with  the  front  view, 
and,  in  this  case,  above  it. 

After  constructing  the  border  lines  the  same  as  in  the  exercises, 
estimate  at  about  what  position  you  wish  the  drawing  of  the  cube  to 


[441 


FREUECTIE1N  I 


Fffo/vr 


CUBE 


S  /O£ 


Br 


[45] 


appear  on  the  paper.  When  you  have  decided  on  this  point  draw  the 
construction  line  A,  A1,  A-,  representing  the  base  line  of  the  front  view. 
Do  not  be  afraid  of  making  this  line  too  long  but  be  very  careful  not  to 
make  it  too  heavy.  On  this  base  line  measure  off  with  your  ruler  a 
distance  of  2"  and  mark  it  with  a  sharp  pencil  or  needle.  Make  points 
B,  B1  as  faint  as  possible,  as  they  must  not  be  seen  when  the  drawing 
is  completed. 

From  points  B,  B1  erect  perpendicular  construction  lines  B  (.'  and 
B'C1  indefinite  in  length.  With  the  45-degree  Triangle  draw  diagonal 
construction  line  B  D  from  point  B  so  it  will  pass  through  vertical  con- 
struction line  B'C1  at  point  E.  The  distance  from  point  B1  to  where 
diagonal  B  I)  passes  through  vertical  line  B^11  at  point  E  will  be  found 
to  be  exactly  2"  if  the  work  has  been  done  accurately. 

The  length  and  height  of  the  front  view  have  now  been  determined. 
Pass  a  horizontal  line,  F  F1,  through  point  E.  This  completes  the 
square.  Study  thoroughly  the  process  of  constructing  a  square  by  the 
aid  of  the  T-Square  and  Triangle  and  with  but  one  measurement. 

As  the  side  and  top  views  of  a  cube  are  both  represented  by  a 
square,  the  faint  construction  lines  projecting  beyond  the  front  view 
both  at  the  side  and  top  may  be  used  to  form  a  pair  of  sides  for  both  the 
top  and  front  views.  Leave  a  neat  space  between  views  for  the  dimension 
lines  and  construct  the  squares  representing  the  side  and  top  views  in 
the  same  manner  as  the  front  view  was  constructed.  With  the  aid  of 
the  foregoing  explanation  and  the  construction  lines  shown  in  the  side 
and  the  top  views,  this  should  be  easily  accomplished.  When  the  three 
views  are  completed  put  in  the  dimension  lines  and  dimensions  as  shown. 
Brighten  or  go  over  the  squares  representing  the  front,  side,  and  top 
views.  When  these  lines  are  inked  they  should  correspond  in  thickness 
to  those  of  the  object  line  in  Figure  VI,  page  23.  Letter  the  plate  and 
put  in  name,  age,  grade,  school,  etc.,  at  the  bottom.  After  all  dirt,  finger 
marks,  and  construction  lines  are  erased,  the  plate,  Projection  I,  is 
completed. 


[46] 


FROJECTIDN    U 


'\r 
A 


\l 


WEDCE 


[48] 


PROJECTION  II— WEDGE 

To  make  a  projection  drawing  of  a  "Wedge  in  three  views  will  require 
three  measurements  only.  In  the  projection  of  an  object  it  is  advisable, 
whenever  possible,  to  draw7  the  front  view  first.  Extend  the  base  and 
top  lines  as  shown  at  A  and  A1,  thus  locating  the  height  of  the  side  view. 
Extend  lines  B  B1  and  E  E1,  thus  locating  the  length  of  the  top  view.  The 
width  of  the  AVedge  shown  in  the  top  view  will,  of  course,  be  the  same  as 
the  width  in  the  side  view.  Locating  the  vertex  of  the  Wedge  so  that 
it  will  l)e  in  the  exact  center  of  the  front  view  can  easily  be  done  without 
the  use  of  the  ruler  by  applying  one  of  the  first  principles  of  geometry, 
that  of  bisecting  a  straight  line  (dividing  a  line  into  two  equal  parts). 
At  the  top  of  the  plate,  Projection  II,  is  a  line  properly  and  geometrically 
bisected.  Place  the  point  of  the  Compass  at  one  end  of  the  line  as  at  1. 
Spread  Compass  so  that  its  distance  will  be  greater  than  half  the  lengt-i 
of  the  line,  and  draw  arcs  2  and  3.  Without  changing  the  adjustment 
of  the  Compass  repeat  the  operation  by  drawing  arcs  i  and  ~>.  In  this 
operation  use  the  other  end  of  the  line  or  point  6  as  a  center.  Draw  a 
line  as  shown  connecting  the  points  of  intersection  of  the  arcs.  This 
line  will  be  found  to  pass  through  the  exact  center  of  the  line  to  be 
bisected. 

Bisect  in  this  manner  the  base  line  of  the  front  view  of  the  Wedge 
thus  locating  the  center  of  the  base.  Draw7  a  vertical  line  through  this 
center  and  extend  it  far  enough  to  locate  the  vertex  of  the  Wedge,  C,  and 
also  the  line,  D  D1,  representing  the  edge  of  the  Wedge  as  seen  in  the  top 
view7.  The  geometrical  solution  at  the  top  can  be  omitted  in  the  finished 
drawing  if  desired.  It  is  assumed  that  by  this  time  the  student  under- 
stands what  lettering  each  individual  drawing  requires,  and  also  which 
lines  are  to  be  brightened  and  which  are  not.  With  this  drawing  that 
part  of  the  explanation  will  be  discontinued. 


PROJECTION  III— HEXAGONAL  PRISM 

Projection  III  is  the  representation  of  a  Hexagonal  Prism  2"  in 
height,  with  a  hole  1/2"  in  diameter  passing  through  it  lengthwise. 

In  discussing  Projection  II  it  was  said  to  be  advisable,  whenever  pos- 
sible, to  draw  the  front  view  first,  but  in  the  construction  of  such  draw- 
ings as  the  Hexagonal  Prism,  the  top  view  should  be  drawn  first,  to  locate 
at  once  the  long  and  short  diameters  or  to  determine  the  exact  width  of 


[491 


PROJECTION  H 


[50] 


the  front  and  side  views.  The  drawing  of  the  top  view  applies  the 
geometrical  principle  of  inscribing  a  regular  hexagon  in  a  given  circle, 
(Fig.  1).  The  diameter  of  the  given  circle  equals  the  long  diameter  of  the 
hexagon,  which  in  this  case  is  two  inches.  In  Figure  1  in  the  upper  right 
hand  corner  of  the  plate  are  shown  two  methods  of  procedure,  lu  both 
methods  it  is  necessary  first  to  construct  the  circle  of  a  given  diameter.  A, 
and  through  the  exact  center  of  this  circle  to  erect  ;i  vertical  center  line, 
B.  By  the  dimensions  shown  in  Figure  1  it  will  be  seen  that  the  radius  of 
the  circle  and  the  length  of  one  side  of  the  hexagon  are  equal.  As  the  sides 
of  a  hexagon  are  all  of  an  equal  length  it  is  plain  that  by  the  aid  of 
the  Compass  or  Divider,  set  to  an  exact  distance  of  one  inch,  or  the 
radius  of  the  circle,  the  six  equal  sides  can  be  easily  located  by  spacing 
them  off  on  the  circumference  of  the  circle,  A.  The  starting  point  in  this 
case  should  be  at  point  C  or  the  point  where  the  vertical  center  line  B 
intersects  circle  A.  The  other  commonly  used  method  of  constructing 
a  perfect  hexagon  is  by  the  use  of  the  T-Square  and  the  30-degree  Tri- 
angle as  shown  in  Figure  I.  This  method  should  be  understood  without 
further  explanation,  as  it  involves  only  the  proper  use  of  the  T-Square 
and  Triangle. 

The  drawing  shows,  as  has  been  previously  stated,  that  a  hole  Vi/' 
in  diameter  is  to  extend  through  this  prism  lengthwise. 

The  top  view  shows  clearly  the  location  of  the  half-inch  hole. 
In  the  side  and  front  views  the  hole  would  of  course  be  shown  by  hidden 
lines;  these  lines  would  be  i//'  apart,  each  1/4"  from  the  center  line 
of   the    view. 

If  this  hole  were  to  extend  only  part  way  through  the  prism  this 
information  would  be  transmitted  without  verbal  explanation  by  extend- 
ing the  vertical  dotted  lines  to  the  required  depth  only,  and  by  giving  a 
dimension  for  this  depth.  The  bottom  of  the  hole  would  be  shown  by  a 
dotted  line  drawn  from  the  bottom  of  one  vertical  line  to  the  bottom  of 
the  other  or  from  one  vertical  dotted  line  to  the  other  at  the  proper 
depth,  thus  showing  the  termination  or  the  bottom  of  the  y*"  hole. 

It  will  be  noticed  that  in  representing  the  front  view  of  the  hexagon 
placed  in  this  position  three  vertical  object  lines  are  necessary,  while  in 
representing  the  side  view  four  are  required.  The  reason  for  this  should 
be  thoroughly  understood  by  the  student.  It  will  also  be  noticed  that  in 
order  to  locate  the  center  line  in  the  side  view  the  geometrical  principle 
of  bisecting  a  straight  line  is  again  used. 


[51] 


If  the  problem  in  Projection  III  involved  the  making  of  a  polygon 
with  more  than  six  sides,  a  different  method  of  construction  would  neces- 
sarily be  used.  In  Figure  IV,  p.  53,  a  convenient  and  easy  method  of 
dividing  a  circle  into  any  number  of  equal  parts  is  given. 

After  drawing  a  circle  of  the  proper  diameter,  draw  through  its 
center  a  horizontal  and  a  vertical  center  line  as  shown  at  A  B  and  C  D. 
Then  divide  the  horizontal  center  line  A  B  into  as  many  equal  parts  as 
it  is  required  to  divide  the  circle — in  this  case  seven.  Divide  the  upper 
half  of  the  vertical  center  line  into  four  equal  spaces  as  1, 2,  3,  and  4,  and 
extend  it  upwards  to  point  E  beyond  the  circle,  a  distance  equal  to  the 
length  of  three  of  these  parts.  Through  point  E  and  the  second  division 
point  from  the  left  of  the  center  on  the  horizontal  line  A  B,  draw  a  line 
intersecting  the  circle  at  point  G.  It  will  be  found  then,  if  the  work  has 
been  accurately  done,  that  the  distance  represented  by  the  heavy  line 
A  G  is  the  required  length  of  each  of  the  seven  sides.  Set  the  Dividers 
to  this  distance  and  step  around  the  circle. 

If  the  top  view  in  Projection  III  were  to  assume  the  shape  of  an 
ellipse,  an  approximately  correct  ellipse  (Fig.  II)  or  a  true  ellipse  (Fig. 
Ill)  could  be  constructed  as  described  below. 

To  construct  an  approximately  correct  ellipse  draw  first  the  hori- 
zontal center  line  A  B  (Fig.  II)  then  the  vertical  center  line,  C  D.  On 
each  of  these  center  lines,  from  their  intersecting  point  E  measure  off 
one-half  of  the  corresponding  long  and  short  diameters  of  the  ellipse. 
On  the  long  diameter,  from  A,  measure  off  a  length  equal  to  the  short 
diameter,  thus  locating  point  F.  Divide  the  remaining  portion  of  the 
horizontal  line  into  three  equal  parts  as  1,  2,  3.  With  E  as  a  center  and 
the  Compass  set  to  a  distance  equal  to  the  length  of  two  of  these  parts, 
as  1  and  2,  draw  arcs  cutting  horizontal  center  line  A  B  at  points  Y  and 
Z.  Set  the  Compass  to  the  distance  Y  Z,  and  with  Y  as  the  center  draw 
arcs  P  and  Q ;  with  the  same  radius,  and  with  Z  as  a  center  draw  arcs 
M  and  N.  With  the  intersecting  points  of  arcs  M  and  P  and  N  and  Q 
and  the  points  Y  and  Z  as  centers  draw  the  ellipse  as  shown  by  the  radial 
dimension  lines. 

In  constructing  a  true  ellipse  it  will  be  necessary  to  draw  from 
the  same  center  two  circles,  one  with  a  diameter  equal  to  the  short  and 
one  with  a  diameter  equal  to  the  long  diameter  of  the  desired  ellipse. 
Divide  the  larger  circle  into  an  equal  number  of  parts  (24  will  be  suffi- 
cient) by  the  aid  of  the  45-degree  and  30-degree  Triangles,  used  singly 


[52] 


and  in  combination.  Connect  these  division  points  with  the  center  of 
the  circles  as  shown.  From  the  division  points  of  the  large  circle  project 
vertical  lines  A,  B,  C,  D,  E,  etc.,  and  from  the  division  points  on  tli<- 
small  circle,  formed  by  the  radii  of  the  large  circle,  project  horizontal 
lines  1,  2,  3,  4,  etc.  Through  the  intersection  points  of  these  correspond- 
ing vertical  and  horizontal  lines,  as  0,  O1  O2,  etc.,  carefully  draw  by  the 
aid  of  the  Irregular  Curve,  the  desired  ellipse. 

PROJECTION  IV— CAST  IRON  RING 

Projection  IV  is  that  of  a  cast  iron  cylindrical  ring.  Two  methods 
of  representation  are  shown,  both  of  which  are  correct.  If  in  drawing 
the  front  and  side  views  of  the  ring,  no  principles  other  than  those 
that  have  been  previously  given  were  to  be  used,  the  front  view  (Fig.  I) 
and  the  side  view  (Fig.  II)  would  be  sufficient.  But  in  the  represen- 
tation of  objects  it  is  often  necessary  to  make  what  is  termed  a  section 
drawing, — a  drawing  of  a  section  or  cut  through  the  object,  (Fig.  III). 

In  drawing  the  section  of  an  object  a  true  representation  must  be 
shown  of  what  the  object  would  look  like  at  the  particular  place  where 
the  object  is  cut  in  imagination.  Imagine  a  cut  made  through  an  object, 
as  with  a  saw,  and  then  show  an  exact  representation  of  that  part  of  the 
object  the  saw  passed  through  as  looked  at  squarely  toward  the  cut  surface. 

This  method  of  representing  an  object,  or  some  particular  part  of 
an  object,  is  used  principally  to  show  more  completely  the  shape,  location, 
or  construction  of  some  part  or  parts  not  clearly  shown  in  the  ordinary 
way.  Advantage  is  generally  taken  of  a  sectional  drawing  to  make  it 
show  from  what  material  the  object  is  to  be  made,  by  crossing  the  sec- 
tion diagonally  with  a  series  of  lines  and  combinations  of  lines,  each 
combination  representing  a  certain  material.  (See  page  56.) 

In  Projection  IV,  Figure  III,  is  shown  a  sectional  drawing  of  the 
cylindrical  ring,  the  line  of  intersection  being  A  A  (Fig.  I).  By  com- 
paring the  section  lines  shown  in  Figure  III  with  the  small  squares  on 
page  56,  properly  sectioned  as  previously  mentioned,  it  will  be  seen  that 
cast  iron  is  the  material  from  which  the  ring  is  to  be  made. 

In  the  execution  of  this  problem  the  usefulness  of  an  occasional 
sectional  drawing  is  by  no  means  fully  covered.  The  problem  is  given 
only  to  acquaint  the  student  with  the  principle  involved. 


[54] 


HZ 


nc.m 


FIG.  I 


r  55 


SECTION   LINES 


C/JST  IRON 


3  r  CEIL 


WPOUGHT!RON 


BRASS 


B/JBBJTT 


WOOD 


[561 


PROJECTION  V— PIPE  CUT  AT  AN  ANGLE 

The  projection  drawing  of  a  piece  of  pipe  to  show  all  required 
dimensions  would  necessitate  but  two  views,  the  front  view  to  show 
the  length,  and  the  top  view  to  show  the  inside  and  outside  diameters. 

If,  for  any  purpose,  this  pipe  were  to  be  cut  at  an  angle,  the  angle 
also  could  be  shown  in  the  front  view,  but  if  for  any  reason  it  were 
required  that  the  exact  shape  of  the  end  cut  at  an  angle  be  shown,  this 
exact  shape  would  have  to  be  developed  or  drawn  in  a  view  parallel  to 
the  cut.  The  drawing  of  a  piece  of  pipe  cut  off  at  one  end  at  an  angle 
of  45  degrees  is  shown  in  Projection  V.  Four  views  are  given  so  that 
all  principles  involved  can  be  easily  understood. 

In  reproducing  this  drawing  the  inside  diameter  should  be  I1/-/', 
the  outside  diameter  2",  and  the  extreme  length  3". 

Draw  the  top  and  front  views  according  to  the  above  measurements, 
and  show  the  top  end  of  the  pipe  cut  at  an  angle  of  45  degrees.  Divide 
the  upper  half  of  the  circle  representing  the  outside  diameter  into  any 
number  of  equal  parts  (12  will  be  sufficient,  as  1,  2,  3,  4,  5,  6,  etc.). 
Draw  the  series  of  lines,  R,  connecting  these  points  with  the  center  of 
the  circle  0;  then  with  the  series  of  lines  X  project  points  1,  2,  3,  4,  etc., 
until  they  intersect  or  cross  line  B  B,  which  represents  the  edge  of  the 
top  of  the  pipe. 

It  has  been  previously  stated  that  if  an  exact  representation  of  the 
end  of  the  pipe  cut  at  an  angle  be  desired,  the  view  of  the  end  would 
have  to  be  made  with  its  center  line  parallel  to  the  cut  B  B. 

Draw  center  line  CC  exactly  parallel  to  BB  as  shown,  and  with 
the  45-degree  Triangle  and  the  T-Square  draw  projecting  lines  Z  from  the 
intersecting  points  of  lines  X  and  line  B  B  through  center  line  C  C. 
This  will  locate  on  center  line  C  C  the  true  length  of  the  slanting  end 
of  the  pipe. 

By  referring  to  the  perspective  drawing  of  this  pipe  it  will  be  seen 
that  the  end  of  a  pipe  cut  at  this  or  any  other  angle  gives  the  appear- 
ance of  an  ellipse.  The  line  representing  an  ellipse  comes  under  the 
head  of  a  line  otherwise  than  straight,  but  which  cannot  be  drawn  with 
a  compass.  It  must  therefore  be  drawn  by  the  aid  of  an  Irregular 
Curve. 


[58] 


[59] 


By  referring  to  the  description  and  use  of  the  Irregular  Curve 
(page  14)  we  see  that  a  series  of  points  directly  in  the  path  of  the  curve 
to  be  drawn  must  be  located. 

Before  proceeding  with  the  location  of  these  points  the  student's 
attention  is  called  to  the  fact  that  the  space  between  the  view  of  the 
outside  and  the  inside  <of  the  pipe  is  blackened  merely  to  add  reality  to 
the  appearance.  In  the  drawing  executed  by  the  student  the  outside  and 
the  inside  of  the  ellipse  must  be  represented  with  lines  corresponding 
in  thickness  to  an  object  line,  and  the  space  between  the  ovals  must  be 
left  white. 

It  will  be  noticed  that  the  points  at  the  termination  or  ends  of 
diagonal  lines  Z  are  marked  to  correspond  with  the  division  points  on 
the  upper  half  of  the  circle  in  the  top  view,  1,  2,  3,  4,  etc.,  and  also 
that  these  points  can  be  directly  traced  through  intersecting  points  on 
line  B  B.  Adjust  the  Bow  Dividers  so  that  one  point  rests  on  0  and 
the  other  point  on  6  of  the  top  view.  With  0  on  C  C  as  a  center,  transfer 
this  distance  to  each  side  of  the  center  line  C  C.  This  locates  the  extreme 
width  of  the  outside  ellipse.  To  locate  the  second  widest  point  adjust 
Dividers  to  the  exact  space  between  point  5  and  line  A  A  in  the  top 
view,  and  transfer  this  distance  as  before  to  each  side  of  the  center  line 
C  C  on  line  5,  series  Z. 

It  is  evident  that  this  distance  is  the  same  as  that  from  point  7  to  line 
A  A  in  the  top  view.  So,  without  readjusting  Divider  points,  transfer 
the  same  distance  each  side  of  the  center  line  C  C  on  line  7.  Continue 
this  process  until  all  points  have  been  located.  If  the  work  has  been 
accurately  done  a  curve  passing  through  all  points  will  produce  an 
ellipse. 

The  ellipse  representing  the  inner  part  of  the  diagonal  end  of  the 
pipe  can  be  located  in  exactly  the  same  manner.  Since  the  inner  circle 
in  the  top  view  is  already  divided  into  the  required  number  of  equal 
spaces  by  the  intersection  of  lines  R,  you  can  proceed  as  before  to  draw 
lines  X  from  these  intersection  points  to  line  B  B.  Then  from  intersect- 
ing points  of  lines  X  and  line  B  B  draw  lines  Z  through  center  line  C  C. 

Transfer  the  distances  from  line  A  A  to  points  on  the  inner  circle 
in  the  top  view,  formed  by  the  intersecting  radii,  over  to  their  proper 
locations  and  on  each  side  of  center  line  C  C.  Construct  the  inner  ellipse 
in  the  same  manner  as  for  the  outside  ellipse. 


[60] 


A  careful  study  of  this  problem  and  the  one  following  must  be  made 
by  the  student,  as  they  involve  a  principle  often  met  with  in  the  proper 
representation  of  objects.  Study  also  the  reason  for  showing  the  diag- 
onal end  of  the  pipe  in  the  side  view  as  follows. 

In  the  front  view  of  a  cube  (Projection  I)  the  height  was  located 
by  drawing  a  line  from  the  intersection  of  vertical  line  B  C  and  base 
line  A1  A2  through  the  other  vertical  line  B1  C1  at  an  angle  of  45 
degrees.  Since  you  know  that  this  drawing  is  correct  and  that  the 
length  of  the  line  representing  the  base  as  B  B1  is  equal  to  the  height, 
B1  E,  the  natural  consequence  of  cutting  the  pipe  in  Projection  AT  at  the 
same  angle  of  45  degrees  can  easily  be  imagined ;  that  is,  the  vertical 
height  of  the  cut  equals  the  diameter  of  the  pipe.  This  being  the  case, 
the  height  of  the  cut  in  the  side  view  equals  its  width.  As  a  consequence, 
a  circle  shows  the  side  view  of  the  cut  end  of  the  pipe. 

To  prove  this  in  your  own  mind,  draw  horizontal  lines  Y  from  inter- 
secting points  on  B  B  through  the  side  view  as  shown,  and  check  or  try 
with  the  Divider  the  distances  from  A-A  to  1,  2,  3,  4,  etc.,  in  both  top 
and  side  views.  In  the  operation  determine  whether  or  not  they  are  of 
the  same  length. 

Hold  a  book  at  arm's  length  from  the  body  with  the  flat  side  of  the 
book  directly  facing  the  eye  and  you  will  see  that  a  view  of  the  book 
in  this  position  shows  its  exact  dimensions.  Hold  the  arm  in  the  same 
position  and  turn  the  book  gradually  until  none  of  the  side  can  be  seen. 
The  edge  will  then  directly  face  the  eye.  So  it  is  in  drawing  the  side 
view7  of  the  cut  on  the  end  of  the  pipe.  Were  the  cut  made  at  a  40- 
degree  angle  with  the  line  B  D  instead  of  a  45-degree  angle,  the  side 
view  would  show  it  wider  than  it  is  high.  Were  it  made  at  a  50-degree 
angle  with  the  line  B  D  instead  of  a  45-degree  angle,  the  side  view 
would  show  the  cut  higher  than  wide. 

This  proves  that  the  side  view  of  an  object  whose  front  view  does 
not  show  all  parts  of  the  object  in  a  vertical  position  does  not  give  the 
true  dimensions  of  these  parts. 


[61] 


PROJECTION  VI— CONE  CUT  PARALLEL  TO  ITS  AXIS 

A  cone  is  a  body  which  has  a  circle  for  a  base  and  which  terminates 
in  a  point  at  the  top.  To  make  the  projection  drawing  of  a  cone  in 
three  views  would  be  a  simple  matter.  To  draw  the  front  view  one  would 
draw  a  triangle  with  a  given  base  and  altitude,  or  height.  As  it  is 
alike  on  all  sides,  the  side  view  would  be  the  same  as  the  front  view.  To 
draw  the  top  view  one  would  draw  a  circle  whose  diameter  would  be 
equal  to  the  diameter  of  the  base  of  the  cone,  with  a  dot  or  point  in  the 
center  of  the  circle  representing  the  top. 

Occasionally  during  the  process  of  representing  an  object  on  paper 
the  outline  of  an  irregular  curve  formed  by  the  intersection  of  a  plane 
with  the  object  must  be  drawn.  A  good  illustration  of  this  is  given  in 
Projection  VI.  The  small  perspective  drawing  in  the  upper  right  hand 
corner  of  the  plate  shows  a  cone  flattened  on  one  side  as  if  a  portion 
had  been  cut  off.  The  fact  that  the  cone  is  round  at  the  base  and  tapers 
to  a  point  at  the  top  would  naturally  cause  the  edge  of  this  flattened 
surface  to  form  a  peculiar  curve. 

In  Projection  VI  the  cut  is  made  in  this  instance  at  one  side  of  and 
parallel  to  the  center  line  or  axis  of  the  cone.  Draw  the  front,  top.  and 
side  views  of  the  cone  so  that  it  will  be  2%"  wide  at  the  base  and 
2%"  high.  Also  draw  the  vertical  lines  D  and  D1  on  the  front  and 
top  views  representing  the  edge  of  the  cut  surface  or  the  cutting  or 
intersecting  plane.  The  exact  location  of  this  line  is  not  important. 

Through  the  center  of  the  circle  representing  the  top  view  draw 
the  horizontal  line  0  R,  and  from  the  point  where  line  0  R  touches  the 
circle  step  off  on  the  circle  seven  or  eight  points,  as  1,  2,  3,  4,  etc.,  with  the 
Bow  Dividers.  From  these  points  draw  lines  W,  connecting  them  with 
the  center  of  the  circle.  From  the  points  1,  2,  3,  4,  etc.,  just  located 
on  the  circle,  project  lines  downward  until  they  touch  line  B  or  the  base 
line  of  the  cone  originally  shown.  From  the  points  where  these  lines. 
(X),  intersect  the  base  line  B  draw  diagonal  lines  Y,  connecting  these 
points  with  the  vertex  or  top  of  the  cone  at  C.  Note  that  the  lines  Y 
cross  diagonally  line  D.  Through  the  points  located  by  the  diagonal  lines 
Y  crossing  line  D  draw  horizontal  lines  Z  through  the  side  view  of  the 
cone. 

The  length  of  line  D1  in  the  top  view  is  the  same  as  the  width  of  the 
cut  side  at  the  base  of  the  cone  as  shown  in  the  side  view  at  a-a.  The 


[62] 


[63] 


height  of  line  D  in  the  front  view  is  the  same  as  the  height  of  the  cut 
side  of  the  cone,  also  shown  in  side  view  on  its  center  line.  There  are 
of  course  as  many  lines  (Z)  between  the  base  and  the  top  of  the  cut  side 
in  the  side  view  as  there  are  points  located  on  the  circle  above  R,  as 
1,  2,  3,  4,  etc.,  in  the  top  view,  because  each  of  these  lines  (Z)  can  In- 
directly traced  back  through  intersecting  points  on  the  front  view  to 
points  1,  2,  3,  4,  etc.,  of  the  top  view. 

Therefore  the  points  1,  2,  3,  4,  etc.,  in  the  top  view  bear  a  direct 
relation  to  the  spacing  of  lines  Z  in  the  side  view.  It  is  to  be  noted  also 
that  the  distances  from  the  intersecting  points  of  lines  W  and  line  Dl 
to  the  intersecting  point  o  of  lines  0,  R  and  D1  are  the  same  as  the 
distances  spaced  off  on  lines  Z  each  side  of  the  center  line  in  the  side  view. 

Using  point  o  in  the  top  view  as  the  center,  set  the  Dividers  to  o  a 
and  transfer  this  distance  to  o  a  on  the  base  line  of  the  side  view  on  each 
side  of  its  center  line.  The  line  a  a  in  this  view  thus  gives  the  width 
of  the  cut  surface  on  the  base  of  the  cone.  Transfer  distances  o  b, 
o  c,  o  d,  etc.,  from  the  top  view,  to  o  b,  o  c,  o  d,  etc.,  on  each  side 
of  the  center  line  in  the  side  view  as  before,  thus  locating  the  points 
through  which  the  natural  path  of  the  curve  must  pass. 

Through  these  points,  with  the  aid  of  the  Irregular  Curve  as  illus- 
trated in  Figure  III,  page  15,  carefully  pass  the  required  curve. 


[64] 


WOOD-WORKING  DRAWINGS 


NOTE.  It  is  not  intended  that  the  wood-working  problems  given 
should  be  strictly  followed  in  the  shop  unless  it  is  so  desired.  It  is 
necessary,  however,  that  the  student  should  drawr  and  thoroughly  under- 
stand all  problems  given,  even  though  not  all  of  them  are  described,  as 
they  were  designed  by  the  author  for  the  purpose  of  covering,  one  step 
at  a  time,  the  practical  methods  of  clearly  and  concisely  representing 
objects  constructed  of  wood.  Number  the  drawings  1,  2,  3,  4,  etc.  In 
cases  where  the  details  are  shown  on  separate  sheets,  give  the  detail 
sheets  the  same  number  and  also  a  sheet  letter,  as  drawing  number  5  for 
the  assembly,  and  drawing  number  5,  sheet  A,  B,  C,  etc.,  for  the  details. 
The  assembly  and  detail  sheets  of  each  object  should  be  fastened  together 
with  a  separate  sheet  which  acts  as  a  cover  or  protector.  This  cover 
sheet  may  be  lettered  as  follows,  for  example :  ' '  Detail  and  Assembly 
Drawing  of  a  Pedestal.  Drawing  number  9.  Drawn  by  Bennie  Drayer, 
Age  14,  Grade  8A;  Date,  January  9th,  1915,  Indianola  School,  Colum- 
bus, Ohio." 

By  keeping  the  drawings  in  their  proper  order  in  the  portfolio 
as  previously  described,  any  set  of  drawings  may  be  located  at  once, 
and  the  work  of  any  student  can  be  seen  by  teacher,  principal,  or  visitor 
at  a  moment's  notice. 


DRAWING  BOARD 

The  Drawing  Board  shown  011  the  opposite  page  is  of  ample  di- 
mensions to  accommodate  a  paper  sufficiently  large  for  the  execution 
of  all  drawings  herein  given. 

This  Drawing  Board  is  composed  of  three  pieces  of  material :  a  top 
which  is  %"  thick,  12"  wide,  and  15"  long,  and  two  cleats,  or  reinforcing 
strips,  which  are  %"  thick,  l1/^"  wide,  and  11"  long.  The  purpose  of 
these  reinforcing  strips  is  to  prevent  the  top  from  warping.  They  are 
to  be  fastened  to  the  under  part  of  the  top,  in  the  position  shown,  by 
means  of  flat-headed  screws. 

The  drawing  of  the  Drawing  Board  should  be  made  with  as  few  meas- 
urements as  possible.  This  is  not  difficult,  as  the  only  principle  involved 
is  the  proper  use  of  the  T-Square  and  the  Triangle.  For  example,  make 
a  12"  measurement  in  one  place  only.  Then  with  the  T-Square  held 
in  proper  position  draw  a  horizontal  line  through  each  of  the  points 
located  by  this  12"  measurement,  using  the  top  edge  of  the  T-Square 
blade  as  a  guide  for  the  pencil.  These  lines  will  locate  the  width  of 
the  board  along  its  entire  length  and  will  also  locate  the  width  of  the 
board  as  shown  in  the  end  view.  The  same  principle  applies  in  locating 
the  length  of  the  board  at  all  points  on  the  top  and  front  views  with 
this  exception :  one  90-degree  edge  of  a  Triangle  is  used  as  a  guide  for 
the  pencil,  while  the  other  90-degree  edge  rests  on  the  top  edge  of  the 
T-Square  blade. 

Note: — Review  the  problem  of  drawing  a  cube,  Projection  I, 
page  45. 


[66] 


IV.K 


5 

a 


I 


0) 


« 


a 


[67] 


PIN  TRAY 

The  general  outline  of  the  Pin  Tray  shown  is  that  of  a  rectangular 
prism  or  a  plain  block  of  wood  y8"  thick,  2y2"  wide,  and  f>"  lonjr. 

At  a  glance  it  can  be  seen  that  the  block  thus  described  is  to  have 
the  top  edges  chamfered  to  a  required  dimension.  This  is  shown  plainly 
in  any  one  of  the  three  views.  The  fact  that  a  dimension  for  this  chamfer 
is  given  at  only  one  point  on  the  drawing  indicates  that  the  size  of  the 
chamfer  continues  to  be  the  same  at  all  points  on  the  ed.se  of  the  tray. 
The  outline  of  the  groove  as  shown  in  the  top  view  with  its  given  dimen- 
sion denotes  its  width  and  shows  that  it  is  semicircular  in  shape  at  botli 
ends.  With  the  radius  of  the  circles  omitted  and  the  distance  between 
centers  given,  as  in  this  case,  it  is  understood  that  the  diameters  of  tin- 
circles  to  be  drawn  equal  the  distance  separating  the  lines  they  are  to 
connect,  or  l1/^".  As  the  radius  of  a  circle  always  equals  the  half  of  its 
diameter,  the  full  length  of  the  groove  is  plainly  but  indirectly  shown. 

The  groove  is  shown  in  the  side  or  front  view  to  extend  the  same 
depth  for  a  distance  of  2%",  or  the  distance  between  the  centers  of  the 
end  circles.  If  it  were  not  to  extend  the  same  depth,  a  dimension  for  its 
depth  at  various  points  between  these  centers  would  be  given.  The  end 
view  shows  by  dotted  lines  the  end  shape  of  the  bottom  of  the  groove, 
which  is  also  circular.  The  proper  placing  of  this  dotted  line  appears 
at  first  an  easy  matter,  but  it  will  require  considerable  thought  on  the 
part  of  the  student.  Considering  that  in  the  top  view  there  is  no  dimen- 
sion given  for  the  exact  location  of  the  groove,  it  will  be  understood 
that  it  is  to  appear  in  the  exact  horizontal  and  vertical  center  of  the  tray. 
The  ends  of  the  dotted  lines  representing  the  bottom  of  the  groove  in 
the  end  view  must  show  the  width  of  the  groove  at  the  top  or  widest 
point,  and  must  appear  at  the  exact  required  distance  each  side  of  the 
vertical  center  of  this  view.  As  the  bottom  of  the  groove  is  circular  in 
shape,  as  previously  explained,  a  point  must  be  located  from  which  the 
circle  can  be  drawn  to  allow  it  to  pass  through  a  point  on  the  end  view 
center  line  representing  the  exact  depth  of  the  groove.  There  are.  there- 
fore, three  given  points  through  which  this  circle  must  pass :  A  and  B  rep- 
resenting the  top  edges,  and  C  the  bottom  center  of  the  groove. 

In  the  upper  right  hand  corner  of  the  plate  is  given  the  geometrical 
principle  involved  in  locating  a  point,  from  which,  when  used  as  a  center, 
a  circle  can  be  passed  through  any  three  points  not  in  a  straight  line. 
Let  1,  2,  3  be  the  points  through  which  the  required  circle  is  to  pass. 

Bisect  the  distance  betwreen  the  points  1  and  2,  allowing  the  bisecting 
line  to  extend  upward.  Bisect  the  distance  between  the  points  2  and  3 


[68] 


ro 
OoiG, 


[69] 


and  extend  the  bisecting  line  upward  until  it  crosses  the  bisecting  line 
of  points  1  and  2.  The  intersecting  point  of  these  bisecting  lines  will 
be  found  to  be  the  desired  point  from  which  a  circle  may  be  drawn 
that  will  pass  through  the  given  points  1,  2,  3. 

Apply  the  same  principle  in  passing  a  circle  through  the  given 
points  A,  B,  and  C  in  the  end  view  and  study  until  thoroughly  under- 
stood. Dimension  the  drawing  as  shown.  Erase  all  construction  lines 
and  the  plate  entitled  "Pin  Tray"  is  completed. 

CLOTHES  LINE  REEL 

Before  attempting  to  draw  the  Clothes  Line  Reel,  review  thoroughly 
the  description  and  use  of  the  Scale  Rule  as  given  on  page  16,  and  at  the 
same  time  space  off  on  a  series  of  lines  a  distance  representing : 

2'  0"        at  the  scale  of  3"       equals  1  foot. 


1'  6" 

'   3" 

i  i         t  t 

8'0"        "     " 

t  I               t  I        Q//                           I  i 

t  i         it 

141/,"      " 

"      "   3" 

"         '; 

2'  6" 

''      "   I1//'      " 

.  .         tt 

1'  9" 

"       "    1U,"        " 

it         t  t 

2'  4" 

.  .           -  .       1  "                  i  i 

t  i         t  . 

-I  /  o//              it        tt 

.  .              .  .         1  //                         4  t 

<  <         .  . 

3'  9-"        "     " 

tt              tt            3^,,               tt 

i  i         i  i 

2'  7i/  "     '  '     '  ' 

t  t  •       t  t       3  /  //         .  . 

t  t         t  l 

K>  C"~          «       "' 

1  1        1  1       i/  '/         « 

t  i         « 

t)    O 

7'2 

2'  3"        "     " 

tt        tt       1Xi/,        « 

<  (         t  ( 

12'  6"      "     " 

(  I               it             q  /  //                 .  . 

78 

t  <         <  t 

Af  Q//                 «          « 

"        ^       %"         " 

tt         tt 

20'  0"      "     " 

««        "       l/^" 

it         tt 

18'  6"      "     " 

«        "       14"         " 

1  1         1  1 

32'  6"      "     " 

<  <          <  <           3   //           <  < 

it         1  1 

11'  6"      "     " 

11     "    A"     " 

1  1         ll 

20'  6"      "     " 

"    »  l/8-    " 

1  1         1  1 

15'  9"      "     " 

t  <         4  <        1  /  //          .  . 
78 

1  1         t  t 

40'  0"      "     " 

t  l          1  1           3  f/           tl 

1  1         t  t 

37'  6"      "     " 

t  t          it           3  //           <  < 

it         it 

By  measuring  accurately  from  center  lines  in  both  horizontal  and 
vertical  directions,  and  by  working  carefully,  the  student  should  be  able 
to  draw  straight  and  curved  lines  in  combination  and  produce  this  plate 
properly  without  further  explanation. 


[70] 


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[71] 


CLOTHES  LIFTER 

The  Clothes  Lifter  shown  is  constructed  of  three  pieces,  namely:  bar, 
handle,  and  spreader.  It  will  therefore  be  necessary  to  make,  aside 
from  the  assembly,  a  detailed  drawing  showing  eacli  piece  in  as  many 
views  as  is  necessary  to  locate  all  dimensions. 

The  sectional  square  drawn  in  the  center  of  the  assembly  shows  the 
size  and  shape  of  the  bar  between  rivets. 

In  the  detail  of  the  bar  both  ends  are  shown  to  be  tapered  on  two 
sides  from  the  rivets  out. 

In  the  front  view  of  the  handle  are  shown  dimensions  for  making 
the  saw  cuts,  while  in  the  end  view  the  handle  is  shown  to  be  round. 

In  the  front  view  of  the  spreader  the  shape  is  shown  to  be  that  of  a 
wedge,  with  sides  concave  to  the  extent  of  y±".  The  end  view  of  the 
spreader  shows  both  width  and  thickness. 

Where  objects  are  constructed  of  several  parts,  as  is  the  case  in  the 
Clothes  Lifter,  a  material  list  must  be  compiled.  In  compiling  a  material 
list  allowance  must  always  be  made  for  material  to  be  wasted  in  the 
process  of  finishing  or  bringing  the  piece  to  its  actual  shape  and  size. 
The  detail  of  the  bar  shows  it  to  be,  when  finished,  1%"  X  I1/*"  X  3'  1". 
In  order  to  make  proper  allowances,  the  material  list  for  the  bar  must 
read:  1  piece,  \y>"  X  I1/-"  X  3"  2",  etc. 

In  the  following  problems  the  student,  after  the  assembly  and 
details  have  been  drawn,  should  be  able  to  furnish  accurate  material 
lists  without  further  help  or  explanation. 

In  compiling  any  material  list  composed  of  numerous  parts  and 
materials,  the  most  concise  method  is  to  make  a  tabulation  as  shown 
below. 


MATERIAL  LIST 
LIBRARY  TABLE 


No.  PIECES  REQD. 

NAME 

SIZE 

MATERIAL 

1 
4 

Top 
Posts 

%"  X  30"  X  46" 
3"  X  3"  X  29" 

Oak 
Oak 

Etc. 

[72] 


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_°/ 

1 


CD 


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•> 


P 

D 


[73] 


FOOT  REST 

The  drawing  of  the  Foot  Rest  presents  a  principle  which  can  very 
often  be  applied,  especially  when  it  is  desired  to  draw  to  as  large  a 
scale  as  possible  within  a  limited  space. 

It  will  be  noticed  in  the  front  view  that  the  length  of  the  top  is  to 
be  16".  This,  drawn  to  a  scale  of  6"  to  the  foot,  or  half  size,  would 
be  8",  while  the  length  of  the  drawing  is  considerably  less.  Since 
there  is  not  room  011  the  paper  for  a  full  half-size  view,  and  since  the 
size  and  shape  of  all  parts  of  the  stool  between  the  legs  are  the  same, 
it  is  customary  and  proper  to  show  this  view  with  a  piece  broken  out ; 
thus  the  legs  and  ends  are  brought  closer  together  than  the  scale 
demands.  The  over-all  dimensions,  however,  must  be  fully  indicated, 
and  the  legs  and  ends  of  the  sides  and  top  must  be  drawn  true  to  scale. 

In  the  top  view  it  is  not  necessary  to  show  the  entire  top  as  the 
corners  are  all  constructed  alike.  In  certain  cases  it  is  customary  and 
proper,  in  order  to  show  clearly  some  particular  part  or  construc- 
tion of  an  article,  apparently  to  break  out  a  section  of  the  surface,  thus 
allowing  the  construction  to  be  shown  clearly  and  with  a  full  line. 

To  a  person  accustomed  to  working  from  a  drawing  this  practice  is 
not  at  all  confusing,  while  its  saving  in  time  and  space  in  drawing  is 
yery  apparent. 


[74] 


[75] 


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[76] 


SHELF,  SLEEVE  IRONING  BOARD,  MAIL  BOX, 
BOOK  AND  MAGAZINE  RACK 

The  drawings  of  the  objects  mentioned  above  will  require  two  sepa- 
rate sheets  for  each,  one  for  the  assembly  and  one  for  the  details.  It  is 
not  essential  that  they  be  drawn  to  one  scale.  Any  convenient  scale  or 
scales  can  be  used,  according  to  the  size  of  the  part  and  its  position  on 
the  drawing  paper.  It  is  desirable,  however,  to  make  all  drawings  on 
the  same  sheet  to  one  scale  whenever  possible. 

By  observing  carefully  each  detailed  part  and  locating  it  in  the 
assembly,  a  complete  knowledge  of  the  working  principles  of  each  com- 
plete object  can  be  obtained. 


[77] 


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[84] 


DETAIL.   DF 

CE]MB  I  NED   BEHHK 
AND  MAGAZINE 


Borrow 


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[85] 


Hurra* 


PEDESTAL 

Since  the  Pedestal  is  of  considerable  size,  and  since  it  is  square,  it 
will  be  necessary  to  draw  only  the  front  view,  aside  from  the  section,  to 
show  clearly  the  shape  of  the  base.  The  base  could  of  course  be  shown 
in  a  top  view,  but  in  that  case  it  would  be  necessary  to  represent  a 
portion  of  its  outline  by  dotted  or  hidden  lines,  as  in  this  view  it  would 
be  in  direct  line  with  the  top. 

Representing  the  base  in  the  manner  shown  not  only  gives  a  clear 
outline  of  the  base  but  shows  also  the  box  construction  of  the  post  as 
well  as  a  full  top  view  of  the  brackets. 

As  previously  explained  on  page  54,  an  imaginary  cut  must  be  made 
in  the  pedestal  at  points  A,  A,  enabling  a  correct  top  view  of  the  lower 
remaining  section  to  be  drawn. 


[86J 


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[87] 


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[88] 


STUDENTS'  FOLDING  DRAWING  TABLE 

In  the  top  view  of  the  Drawing  Table  it  will  be  noted  that  the 
under  side  is  shown  in  full  lines,  which  is  exactly  contrary  to  all  prin- 
ciples heretofore  given  regarding  hidden  lines. 

This  is  permissible,  however,  when  such  a  view  does  not  conflict  with 
the  clear  representation  of  some  other  part  of  the  object.  It  will  also 
be  noticed  that  the  top  view  is  drawn  parallel  with  the  top  of  the  table 
which  is  on  a  slant.  This  is  done  to  show  the  under  section  of  the  top 
in  its  true  dimensions.  If  the  top  were  shown  directly  above  the  front, 
a  foreshortening  of  the  top  in  the  top  view  would  be  the  result.  The 
greater  the  slant  given  to  the  table  top,  the  greater  would  be  the  fore- 
shortening. 


[90] 


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[92] 


INKING  AND  TRACING 
INKING 

If  an  entire  volume  were  to  be  written  on  the  use  of  drawing  ink 
and  inking  tools,  a  certain  amount  of  careful  inking  practice  would 
still  be  necessary  before  proper  results  could  be  obtained.  Consider- 
ing this  fact,  and  believing  that  many  who  use  this  text  will  do  only 
a  moderate  amount  of  ink  work,  it  has  been  deemed  advisable  to  give 
merely  a  few  instructions  and  precautions  which  will  enable  the  student 
to  obtain  neat  and  accurate  results. 

A  quill  will  be  found  connected  with  the  stopper  of  each  bottle  of 
drawing  ink.  This  is  to  be  used  in  tilling  the  drawing  pens.  Never  dip 
the  pen  directly  into  the  ink.  Hold  the  pen  in  the  left  hand  in  a  per- 
pendicular position,  with  the  handle  at  the  top ;  then  by  placing  the  quill 
filled  with  ink,  and  held  in  the  right  hand,  between  the  points  of  the  pen 
blades  the  ink  will  flow  from  the  quill  to  its  proper  position  between  the 
blades  at  the  point.  Put  no  more  than  three-sixteenths  of  an  inch  of  ink 
in  the  pen. 

Make  sure  that  not  one  particle  of  ink  rests  on  the  outside  of  the 
pen  blades.  If  ink  is  left  on  the  outside  of  the  pen  it  will  come  in 
contact  with  the  T-Square  blade  or  the  edge  of  the  Triangle.  A  flow 
of  ink  will  thus  be  started  from  the  inside  of  the  pen  to  the  paper  or 
even  under  the  T-Square  or  Triangle,  and  an  ugly  blot  will  be  the 
result.  It  is  best  to  have  near  at  hand  a  good  pen-wiper1  so  that  all 
superfluous  ink  on  the  outside  of  the  pen  can  be  removed  before  the 
pen  is  brought  in  contact  with  the  paper. 

After  the  pen  has  been  properly  filled,  place  the  T-Square  or 
Triangle  parallel  to  but  not  quite  in  contact  with  the  line  to  be  traced. 
Keep  the  pen  in  a  position  perpendicular  to  the  drawing  paper  and  place 
the  point  on  the  line  so  that  the  back  of  the  pen  will  touch  the  edge  of 
the  T-Square  or  Triangle  that  is  to  act  as  a  guide.  Never  let  the  point 
of  the  pen  touch  the  edge  of  the  T-Square  or  Triangle,  as  this  will 
immediately  start  the  ink  flowing  under  it. 

In  inking  over  a  line  keep  the  handle  of  the  pen  in  a  plane  perpen- 
dicular to  the  paper  but  allow  it  to  slant  a  little  in  the  direction  that 
the  line  is  to  be  drawn. 

1The  pen-wiper  should  be  a  piece  of  material  free  from  lint,  such  as  the  back  of  an  old 
kid  glove  or  a  piece  of  chamois  skin. 


[93] 


Never  lay  away  a  pen  even  for  a  few  minutes  without  first  removing 
all  ink  from  between  the  points,  as  the  ink  dries  very  quickly.  If  it  is 
allowed  to  dry  it  must  be  scraped  out,  and  this  is  injurious  to  the  pen. 

By  a  turn  of  the  set  screw  on  the  front  side  of  the  pen  the  thickness 
of  the  line  can  be  regulated.  After  obtaining  the  right  thickness  by 
experimenting  on  a  piece  of  scrap  paper,  commence  at  the  top  of  the 
drawing,  working  downward,  drawing  all  horizontal  object  lines  first. 
Nothing  must  touch  these  lines  until  they  are  perfectly  dry.  Then  com- 
mence at  the  left  side  to  draw  the  vertical  object  lines.  In  doing  this, 
work  away  from  the  wet  lines.  Draw  all  lines  that  are  to  be  of  the 
same  thickness  before  resetting  or  readjusting  the  pen.  (Be  sure  that 
the  pen  is  always  clean  and  free  from  any  foreign  substance.) 

After  all  lines  of  one  thickness  are  drawn,  readjust  the  pen  and 
proceed  in  the  same  manner  to  draw  lines  of  another  thickness. 

In  inking  drawings  composed  of  straight  and  curved  lines  it  is  always 
advisable  to  draw  the  circles  or  parts  of  circles  first,  as  it  is  easier  per- 
fectly to  adjust  straight  lines  to  circles  than  it  is  to  adjust  circles  to 
straight  lines. 

TRACING 

When  an  inked  drawing  is  desired  for  exhibition  purposes  a  good 
hard  surfaced  paper  should  be  used ;  otherwise  an  ordinary  paper  can 
be  used  for  pencil  work,  which  may  be  traced  in  ink  on  a  good  quality 
of  tracing  paper  or  tracing  cloth,  from  which  any  number  of  blue  prints 
can  be  made.  Before  any  inking  is  done  on  the  tracing  cloth,  scrape 
from  a  stick  of  chalk  a  small  quantity  of  powder  and  with  a  dry  cloth 
rub  this  powder  over  the  surface  of  the  tracing  cloth.  This  will  remove 
any  moisture  or  grease  and  will  allow  the  ink  to  flow  freely  and  evenly. 


[94] 


SHEET    METAL    DRAWING 


In  a  complete  execution  of  a  drawing  of  any  article  constructed  of 
one  or  more  pieces  of  sheet  metal  there  must  be,  in  addition  to  the 
regular  two  or  three  view  projection  drawing,  a  drawing  showing  the 
article  completely  unfolded.  Sheet  metal  constructions,  as  far  as  pos- 
sible, are  made  from  one  piece  of  material.  The  laying  out  of  one  or 
more  unfolded  surfaces  is  commonly  called  a  Development. 

The  dimensions  of  parts  when  finished  and  the  kind  of  joints  to  be 
used,  whether  soldered,  lapped,  etc.,  are  to  be  shown  in  the  two  or 
three  view  mechanical  projections.  It  is  from  the  information  given  in 
these  projections  that  the  development  is  drawn. 

NOTE.  Students  should  construct  the  following  sheet  metal  prob- 
lems from  heavy  paper  or  card  board,  no  matter  whether  they  intend 
making  them  from  metal  or  not.  This  will  ensure  an  absolute  under- 
standing of  the  principles  involved  as  illustrated  in  the  drawing. 

The  educational  value  in  all  pattern  drawing  lies  more  in  being 
able  properly  to  develop  the  projects  as  drawn  than  in  the  ability  to 
make  them  from  patterns  developed  by  others.  All  drawings  should 
be  made  by  each  student  in  the  order  shown. 


[95] 


BREAD  PAN 

The  first  problem  in  sheet  metal  drawing  is  a  common  Bread  Pan 
with  which  all  are  familiar.  It  is  constructed  of  tin  with  lapped  corner 
joints.  A  wire  is  to  encircle  the  top  completely  and  is  to  be  covered 
by  a  projecting  portion  of  the  sides  of  the  pan.  Allowance  for  this  must 
be  made  in  the  development. 

The  drawing  shows  the  pan  to  have  a  bottom  S1/^"  wide  and  1" 
long.  The  pan  is  to  be  21/2//  in  height.  The  sides  have  a  flare  or  slant 
of  y<r>"  all  around.  The  lap  at  the  corners  will  be  1^",  and  when 
folded  or  finished  the  top  edge  of  this  lap  is  to  be  securely  held  in 
place  by  the  stiffening  wire  which  is  covered  with  the  projecting 
portion  of  the  sides. 

In  laying  out  the  development  it  is  well  for  the  beginner  to  dis- 
tinguish clearly  between  the  cutting,  bending,  and  construction  lines  in 
order  that  he  may  not  become  confused. 

In  the  case  of  the  Bread  Pan  development  shown,  the  full  heavy 
line  represents  where  the  metal  is  to  be  cut,  while  the  dotted  line  repre- 
sents the  place  for  bending.  Light  full  lines  represent,  as  usual,  the 
construction. 

To  draw  the  development  lay  out  first  to  the  dimensions  shown  in 
the  mechanical  drawing  a  rectangle  representing  the  bottom  of  the 
pan.  Set  the  Dividers  to  a  distance  equal  to  the  slant  height  of  the 


[96] 


P/7/V 


hi 


-35 


~T 

SfOE 


BOTTOM 


MEN  T 


[97] 


sides  and  step  off  this  distance  in  a  horizontal  direction  from  the  ends 
of  the  rectangle  just  drawn.  Also  step  off  the  same  distance  outward 
in  a  vertical  direction  from  the  sides  of  the  rectangle.  Care  should 
be  taken  not  to  confuse  the  slant  height  with  the  vertical  height  of  the 
pan.  The  height  given  as  2 1//'  is  the  vertical  height.  The  slant 
height  is  taken  from  the  bottom  to  the  extreme  top  in  the  direction  of 
the  flaring  sides  of  the  pan  in  the  mechanical  drawing. 

After  these  points  representing  the  slant  height  of  the  pan  are  located 
from  both  sides  and  both  ends  of  the  rectangle  in  the  development,  draw 
lines  through  them  with  T-Square  and  Triangle  parallel  to  the  sides 
and  ends  of  the  rectangle.  These  lines,  if  continued  outward  or  upward, 
will  cross  or  intersect  and  thus  form  a  second  rectangle  which  will 
represent  the  exact  location  of  the  finished  top  edge  in  the  developed 
pattern. 

Extend  the  lines  of  the  first  rectangle  until  they  cross  or  intersect 
the  lines  of  the  second  or  larger  rectangle,  and  from  these  intersections, 
as  at  A,  step  off  a  distance  equal  to  the  slant  or  flare  of  the  pan,  which, 
as  previously  explained,  is  Vii"-  From  the  points  just  located  pass 
lines  B  through  the  corners  D. 

When  the  work  thus  far  described  is  accurately  accomplished,  the 
attention  must  be  directed  to  the  proper  construction  of  the  lap.  This 
is  done  by  extending  the  sides  and  cutting  them  to  an  angle  yet  to  be 
determined,  so  that  the  upper  edge  of  the  lap  \vhen  the  pan  is  completed 
will  lie  exactly  parallel  to  the  top  edge  of  the  end  of  the  pan. 

To  construct  this  angle  a  point  on  the  top  edge  of  the  end  of  the 
pan  must  be  located  that  will  represent  the  exact  position  to  be  taken  by 
the  point  of  the  lap  when  the  pan  is  completed.  The  end  of  the  pan 
shows  the  lap  to  extend  along  the  top  edge  for  a  distance  of  I1/-/' 
from  each  side.  Measure  off  this  distance  on  the  end  development  as 
shown  at  C  and  pass  a  line  from  point  C  through  corner  D. 

As  this  shows  the  exact  position  that  must  be  taken  by  the  lap  when 
the  pan  is  completed,  triangle  D  E  C  on  the  end  cannot  be  other 
than  the  exact  shape  of  the  lap  to  be  located  at  the  ends  of  both  of 
the  sides. 


98  ] 


It  is  evident  that  the  shape  of  this  lap  is  triangular.  It  is  also  evident 
that  the  length  of  lines  B  on  the  sides  and  ends  of  the  pan  is  the  same. 
This  being  true,  it  is  plain  that  the  length  of  one  side  of  the  triangle 
is  equivalent  to  the  slant  height  of  the  pan  or  line  B  whieli  has  pre- 
viously been  located.  To  transfer  the  remaining  sides  of  the  triangle 
located  on  the  ends  of  the  pan  to  their  true  position  at  the  ends  of  the 
sides,  set  the  Compass  to  the  distance  C  E,  or  1V/'.  With  the  point 
of  the  Compass  placed  at  point  E  on  the  end  of  the  sides  draw  the  arc 
of  a  circle  F. 

Set  the  Compass  to  the  distance  D  C,  and  with  the  point  of  the  Com- 
pass on  D  draw  arc  G.  From  the  intersecting  point  of  arcs  F  and  G 
draw  lines  H  and  I  through  E  and  D.  The  triangle  representing  the 
position  to  be  taken  by  the  lap  on  the  end  of  the  pan  when  finished  is 
thus  transferred  to  its  correct  position  at  the  end  of  the  sides  and 
becomes  a  true  outline  of  the  lap.  As  the  pan  is  of  an  equal  height  and 
flare  on  all  sides  the  four  corners  will  necessarily  be  constructed  alike 
and  can  be  drawn  as  a  whole  instead  of  singly.  This  simplifies  the 
work  and  also  makes  it  more  nearly  possible  to  obtain  an  accurate  result. 

The  allowance  necessary  as  shown  at  J  for  bending  the  metal  over 
the  reinforcing  wire  depends  on  the  size  of  wire  used. 

Special  attention  should  be  given  to  the  transferring  of  an  angle 
from  one  position  to  another  by  means  of  the  Compass,  as  this  principle 
is  extensively  used  in  some  of  the  problems  to  follow. 


[99] 


DUST  PAN 

The  principles  involved  in  the  development  of  the  Dust  Pan  shown 
are  practically  the  same  as  those  involved  in  the  development  of  the 
Bread  Pan  previously  given.  The  exceptions  are  that  a  double  angle 
has  to  be  contended  with,  and  that  the  back  of  the  Dust  Pan,  corre- 
sponding in  shape  to  the  side  of  the  Bread  Pan,  is  extended  to  form 
the  hood. 

By  means  of  a  carefully  executed  two-view  mechanical  drawing  the 
true  view  length  of  every  necessary  line  can  be  located. 

In  constructing  the  development  draw  first  the  bottom  of  the  pan, 
making  it,  as  shown,  11"  wide  in  front,  9"  wide  at  the  back,  and  8" 
deep.  The  vertical  height  of  the  pan  is  shown  to  be  2",  with  a  flare 
of  1/2"  &t  the  top.  It  is  necessary,  then,  in  order  to  have  the  finished 
pan  2"  high,  to  deal  only  with  the  slant  heights  in  the  development. 
Therefore  lay  off  the  widths  of  the  side  and  the  back  in  the  develop- 
ment equal  to  the  slant  height  of  the  pan.  The  length  of  the  back 
at  its  narrowest  point  must  remain  the  same  as  the  width  of  the 
bottom  at  the  back,  or  9".  As  the  sides  and  back  have  a  flare  of  Vi/'j 
the  extreme  length  of  the  back  will  be  9"  plus  1X>"  at  each  end,  or  10". 
As  the  back  is  a  continuation  of,  and  directly  connected  with  the 
bottom,  so  the  hood  is  a  continuation  of,  and  directly  connected  with 
the  back.  It  will  be  noticed  in  the  development  that  the  length  of 
the  hood  varies  at  different  points.  Being  directly  connected  with 
the  back,  the  length  of  one  side  of  the  hood  remains  the  same  as  the 
length  of  the  side  of  the  back  with  which  it  is  directly  connected.  The 
true  length  and  width  of  the  hood  can  be  seen  plainly  in  the  top 
view  of  the  mechanical  drawing,  the  extreme  length  being  A  B,  and 
the  width  2". 

In  order  to  complete  the  development  of  the  sides  draw  a  line,  C  D, 
at  an  angle  of  90  degrees,  or  perfectly  square  with  the  bottom  of  the 
side,  and  pass  this  line  through  the  point  F  representing  the  exact 
corner  of  the  pan.  Were  the  sides  of  the  finished  pan  straight  this  line 
would  represent  the  cutting  line,  but  as  they  are  to  have  a  flare  of 
!/£"  it  will  be  necessary  to  lay  off  this  flare  on  the  top  edge  of  the 
pan  from  line  C  D,  as  shown  at  G.  Measure  off  on  the  line  representing 
the  top  edge  of  the  side  a  distance  equal  to  the  width  of  the  hood, 


[100] 


DUST     P/7/V 


Sorrow 


c 


[101] 


or  2"  from  G  to  H,  as  this  is  the  position  to  be  taken  by  the  ends  of 
the  hood  in  the  finished  pan.  Lay  off  the  lap  in  exactly  the  same 
manner  as  described  for  the  Bread  Pan  and  make  proper  allowance  at 
the  ends  of  the  hood  for  soldering  surface  as  shown.  For  strengtli  and 
to  stiffen  the  upper  edges  of  the  sides,  a  wire  reinforcement  should  be 
run  along  the  slant  edges  of  the  sides  continuing  in  one  piece  along 
the  edge  of  the  hood. 

The  handle  being  V  square,  the  lines  A,  B,  C,  D,  and  E  in  the 
handle  development,  will  be  1"  apart  and  parallel  to  each  other. 
The  lengths  of  these  lines,  as  shown  in  the  side  view,  are  to  be :  A,  4%" ; 
B,  4";  C,  4";  D,  43/8";  and  E,  43/8"  long.  Lines  B  and  C  must  be 
extended  about  1/2"  or  %",  and  lines  D  and  E  also  so  as  to  form  laps 
F  and  G.  These  laps,  when  soldered  to  the  pan  as  shown  in  the 
mechanical  and  perspective  views,  support  the  handle.  The  lines  B 
and  C  must  also  be  extended  at  the  end  opposite  lap  F,  a  distance  of  1", 
to  form  the  closed  end  of  the  handle,  H.  Around  this  closed  end  and  also 
on  line  A  a  small  allowance  must  be  made  for  solder  contact. 

LAWN  SPRINKLER 

The  Lawn  Sprinkler  shown  is  constructed  entirely  along  straight 
lines.  The  perspective  drawing  shows  it  to  have  the  appearance  of 
being  constructed  from  square  tubing,  but  this  is  not  the  case.  If 
properly  used,  a  piece  of  metal  8^/2"  wide  and  1414"  long  will  be  suffi- 
cient to  construct  the  top,  the  bottom,  and  all  inside  and  outside  edges. 

The  general  dimensions  show  the  sprinkler  to  be  6"  square  and 
V  deep,  and  the  opening  in  the  center  to  be  S1/^"  square.  The  section 
marked  A  is  the  top;  B  is  the  bottom;  C,  C,  C,  C  are  the  four  out- 
side edges  which  are  to  be  bent  upward;  D,  D  are  the  two  inside 
edges  which  are  also  to  be  bent  up.  E,  E  when  bent  up,  and  the  bottom, 
B,  bent  over  in  place,  form  the  remaining  inside  edges.  All  joints  are 
supposed  to  be  soldered,  and  a  small  allowance  is  made  on  one  section 
of  each  joint  for  a  lap,  F,  to  aid  in  giving  more  contact  surface  for  the 
solder.  All  laps  are  to  be  on  the  inside  and  a  hose  coupling  is  to  be 
soldered  on  the  side  as  shown.  The  perforations  in  the  top,  marked  G, 
must  be  punched  carefully  and  not  be  over  -fa"  in  diameter. 


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[103] 


WATER  PAIL 

The  Water  Pail  shown  is  12"  in  diameter  at  the  top,  8"  in  diameter 
at  the  bottom,  and  8"  high.  It  is  necessary,  to  get  the  development  of 
this  pail,  to  draw  an  exact  view  (A,  B,  C,  D)  witli  a  vertical  line  E 
passing  through  its  exact  center.  Extend  the  lines  A  C  and  B  D, 
representing  the  sides  of  the  pail,  downward  until  they  cross  each 
other  on  center  line  E  at  point  F;  set  the  Compass  at  point  F  and 
draw  an  arc  of  a  circle  through  points  A  and  B.  From  the  same 
center  draw  the  arc  of  a  circle  through  points  C  and  D.  Compute  the 
circumference  of  the  pail  at  the  top  and  locate  this  distance  on  the  first 
arc  drawn  so  that  the  half  of  this  distance  will  lie  on  each  side  of  the 
center  line  E,  as  at  G  and  H. 

NOTE.  A  very  convenient  plan  for  locating  the  proper  circular 
length  (or  circumference  of  the  pail  at  the  top)  on  the  development 
of  the  side  of  the  pail,  is  to  draw  a  circle  of  proper  diameter  on  a  piece 
of  card  board  and  to  cut  it  out  with  a  pair  of  scissors.  The  required  dis- 
tance can  then  be  easily  measured  along  the  edge  of  the  card  board  with 
a  tape-line  and  transferred  to  its  proper  position  on  the  drawing,  with 
a  pair  of  dividers. 

Draw  a  line  through  center  F  and  point  H,  also  one  through  center 
F  and  point  G.  This  will  determine  the  angle  of  the  cuts  to  be  made. 
The  circumference  of  the  bottom  of  the  pail  will  not  have  to  be  com- 
puted, as  the  proper  points  on  the  second  arc,  representing  the  bottom 
of  the  pail,  have  been  automatically  located  by  the  intersection  of  this 
arc  with  the  lines  passing  through  F  II  and  F  G.  The  pail  will,  of 
course,  have  a  wire  reinforcement  around  the  top,  and  the  proper  allow- 
ance for  tin  must  be  made  according  to  the  size  of  the  wire  used. 

A  little  study  must  also  be  given  the  method  of  inserting  the  bottom 
and  of  joining  the  sides  to  it  so  that  the  completed  pail  will  not  vary 
from  the  original  dimensions. 

In  the  drawing  showing  the  enlarged  section  of  the  lap  joint  it  will 
be  seen  that  a  double  allowance  must  be  made  on  one  end  of  the  pattern 
for  the  side  of  the  pail,  while  on  the  other  end  but  a  single  allowance 
will  be  necessary.  These  lines  representing  the  allowances  must  be 
drawn  parallel  with  lines  H  F  and  G  F,  and  will  not,  therefore,  pass 
through  center  point  F.  The  development  of  the  bottom  will  be  8" 
in  diameter,  as  given,  with  the  necessary  allowance  for  the  bend,  as 
shown  in  the  enlarged  drawing  of  the  bottom. 


[104] 


[105] 


SUGAR  SCOOP 

For  the  development  of  the  Sugar  Scoop  it  will  be  necessary  to  have 
an  end  and  side  view  drawn.  The  curve  shown  in  the  side  view  repre- 
sents the  shape  of  the  finished  scoop  from  a  side  view.  It  may  be  drawn 
to  accord  with  the  individual  taste  of  the  designer.  As  the  cud  and 
back  views  are  represented  by  circles  of  the  same  diameter  it  does  not 
make  any  material  difference  which  is  named  the  end  or  which  is  named 
the  back. 

The  only  real  value  of  a  back  view  is  to  have  a  space  that  does  not 
conflict  with  the  rest  of  the  drawing  on  which  to  show  the  proper 
location  of  the  handle.  This  view  gives  the  true  widths  of  the  handle 
at  its  extreme  ends. 

Divide  the  circles  representing  the  back  and  end  views,  shown  directly 
over  the  side  and  top  views,  into  an  even  number  of  equal  parts.  (In 
this  case  twelve  will  be  sufficient.)  Project  these  division  points  down- 
ward and  through  the  side  and  top  views  as  shown.  Through  the  inter- 
secting points  of  these  projected  lines  and  the  curve  of  the  side  view  draw 
horizontal  lines  A,  B,  C,  D,  E,  F,  and  G.  Through  the  intersecting 
points  1,  2,  3,  4,  etc.,  of  lines  A,  B,  C,  etc.,  and  the  lines  projected  from 
the  division  points  on  the  circle  representing  the  end  view,  pass  a  curved 
line  representing  the  opening  in  the  front  of  the  scoop  shown  in  the 
top  view.  This  should  be  done  with  the  Irregular  Curve  as  described 
on  page  14. 

To  draw  the  development  of  the  scoop  (Fig.  I)  extend  line  H  repre- 
senting the  edge  of  the  back  in  the  side  view  across  the  paper.  On  this 
line  locate  a  distance  equal  to  the  circumference  of  the  scoop,  in  this 
case  7.06",  or  about  7TV'.  (Calculate  this  circumference.)  Divide  this 
distance  into  as  many  equal  parts  as  are  in  one  of  the  circles  repre- 
senting the  end  view.  Through  each  of  these  division  points  erect 
perpendiculars  to  A,  B,  C,  D,  E,  F,  G,  and  H;  at  points  o,  o,  o,  etc.,  as 
shown  in  Figure  I,  and  through  intersecting  points  o,  o,  o,  etc.,  pass 
the  required  curve. 

In  the  scoop,  as  in  the  pail  previously  drawn,  the  lap  joint  is  used. 
The  allowance  for  this  joint  must  be  twice  as  much  at  one  end  as  at 
the  other. 


[106] 


[107] 


In  Figure  II  is  shown  an  easy  method  of  dividing  a  given  distance 
into  any  number  of  equal  parts.  Let  A  B  represent  the  given  line 
or  distance  to  be  divided.  From  one  end  draw  a  line,  A  (.',  at  any 
convenient  angle.  With  the  Dividers  set  at  any  convenient  distance, 
step  off  on  this  line  as  many  spaces,  or  points — 1,  2,  3,  etc. — as  it  is 
desired  that  the  given  line  AB  be  divided  into.  Set  the  45-degree 
Triangle  so  that  its  edge  covers  point  B  on  the  given  line,  and  point  9 
on  the  line  A  C.  With  the  45-degree  Triangle  held  in  this  position 
place  the  30-degree  Triangle  so  that  its  edge  will  come  in  direct  contact 
with  the  edge  of  the  45-degree  Triangle  as  shown.  With  the  30-degree 
Triangle  held  firmly  in  this  position  slide  the  45-degree  Triangle  up- 
wards, keeping  it  constantly  in  contact  with  the  30-degree  Triangle, 
until  the  edge  of  the  45-degree  Triangle  covers  point  8.  Mark  the  point 
on  given  line  A  B  that  is  crossed  at  this  time  by  the  edge  of  the  45- 
degree  Triangle,  and  again  slide  it  upward  until  point  7  is  covered. 
Continue  this  process  until  all  points  on  diagonal  line  A  C  have  been 
covered,  and  it  will  be  found  that  the  given  line  A  B  has  been  equally 
divided  into  the  required  number  of  spaces. 

NOTE.  The  geometrical  principle  involved  in  dividing  a  given  line 
into  any  number  of  equal  spaces  should  be  dwelt  upon  until  thoroughly 
understood.  It  is  simple  and  accurate. 

Figure  III  shows  the  side  view  of  the  handle  of  the  scoop  and  gives 
the  method  of  its  development.  This  side  view  can  be  drawn  from  the 
dimensions  of  the  handle  given  in  the  side  view  of  the  scoop.  With  the 
Dividers  step  off  a  series  of  spaces  on  the  side  view  as  shown  in  Figure 
III;  then,  by  stepping  off  in  a  straight  line  the  same  number  of  spaces, 
an  approximate  length  of  the  handle  will  be  located.  With  the  width 
of  the  handle  given  at  each  end  as  shown  in  the  back  view  of  the  scoop 
and  the  length  located,  develop  the  handle  as  shown  in  Figure  III. 
Figure  IV  represents  a  section  of  the  handle  showing  the  edges  turned 
over.  Determine  the  amount  to  be  turned  over  and  add  this  to  each 
side  of  the  development  as  shown  in  Figure  III.  To  allow  for  the 
construction  as  shown  in  Figure  V  makes  it  necessary  that  allowance 
be  made  on  the  back  (Fig.  VI)  for  the  metal  to  turn  over  and  form 
a  rim  around  the  edge  of  the  scoop. 


[108] 


FLOAT  BALL 

In  the  development  of  the  Float  Ball  illustrated,  the  patterns  for  the 
several  sections  are  drawn  in  exactly  the  same  manner  as  was  the  pattern 
for  the  side  of  the  pail,  (page  105).  It  will  be  seen  that  the  complete 
ball  is  composed  of  6  sections,  A,  B,  C,  two  of  each  of  which  are 
required. 

Draw,  first,  a  circle  of  the  proper  diameter,  3",  and  erect  the 
vertical  center  line  D.  Divide  the  circle  just  drawn  into  twelve 
equal  parts,  1,  2,  3,  4,  5,  etc.,  commencing  at  the  intersection  of  the 
circle  with  center  line  D  as  at  point  1.  Connect  by  horizontal  lines, 
E,  F,  G,  II,  and  I  representing  the  edges  of  the  sections,  points  12  and 
2,  11  and  3,  10  and  4,  9  and  5,  and  8  and  6.  Also  connect  points  1  and 
2,  2  and  3,  and  3  and  4,  etc.,  as  shown,  with  lines  J,  K,  L,  M,  N,  0,  etc. 

Continue  lines  K  and  L  upward,  as  shown,  until  they  intersect  center 
line  D  at  points  13  and  14,  thus  locating  the  proper  radii  to  be  used  in 
the  laying  out  of  the  different  patterns,  as  Figures  II,  III,  and  IV. 
From  lines  E,  F,  G,  H,  and  I,  which  are  the  diameters  of  the  sections, 
the  circumference  of  the  ball  at  various  levels  can  be  computed.  The 
outside  circular  length  of  each  pattern  equals  the  circumference  of  the 
sections  just  found.  The  slant  cuts  of  the  ends  of  the  patterns  are 
located  by  passing  a  line  from  the  radial  center  of  each  pattern  through 
the  points  marking  its  circular  length,  as  shown  in  Figures  II,  III, 
and  IV. 

The  circular  length  can  easily  be  measured  on  each  pattern  by  the 
method  described  in  the  development  of  the  pail. 


[110] 


[111] 


SINK  STRAINER 

The  problem  of  developing  the  Sink  Strainer  is  one  that  will  require 
the  close  attention  of  the  student.  Constructed  as  it  is,  it  is  im- 
possible to  give  the  true  length  of  all  lines  in  two  or  three  views,  and  as 
a  development  is  composed  entirely  of  true  lengths  it  is  necessary  that 
a  method  for  determining  the  true  length  of  a  foreshortened  line  be  given 
and  mastered. 

In  the  side  view  line  A,  and  in  the  top  view  lines  B,  C,  D,  E,  F,  G, 
H,  and  I  are  shown  in  their  true  lengths.  Lines  J  and  K  of  the  top 
view  represent  the  front  corners  of  the  strainer  as  shown  at  J  and  K 
in  the  perspective,  but  do  not  represent  their  true  length ;  neither  do 
lines  L,  M,  and  N  in  the  side  view.  As  the  true  lengths  of  all  fore- 
shortened lines  can  be  determined  in  the  same  manner,  the  attention 
of  the  student  is  called  to  the  method  used  in  determining  the  true 
length  of  lines  J  and  K  in  the  top  view.  At  a  perfect  right  angle  with 
line  J  draw  the  two  parallel  lines  from  each  end  of  this  line  J,  as  lines 

1  and  2.     Parallel  with  line  J,  and  in  any  convenient  location,  draw 
line  3.  From  the  intersection  of  lines  3  and  1  measure  off  on  line  1  a  dis- 
tance equal  to  the  vertical  height  of  lines  J  and  K  as  shown  in  the  side 
view  to  be  4".    Draw  line  J1  K1  connecting  the  intersecting  point  of  lines 

2  and  3  with  the  vertical  height,  as  measured  off  on  line  1.     The  true 
length  of  lines  J  and  K  will  be  the  length  of  diagonal  line  J1  K1. 

After  locating  in  the  same  manner  the  true  lengths  of  all  foreshort- 
ened lines  proceed  to  draw  the  development  as  follows: 

By  examining  and  studying  carefully  the  side  view  and  the  per- 
spective it  will  be  seen  that  the  altitude  or  the  true  height  of  the  tri- 
angular shaped  front  is  equal  to  the  length  of  line  J  in  the  side  view. 
So  measure  this  height  off  on  a  vertical  center  line  and  draw  line 
C,  making  half  of  its  length  lie  on  each  side  of  the  center  line  in  a 
horizontal  direction.  Draw  lines  J1  and  K1  (which  are  the  true  lengths 
of  lines  J  and  K)  as  shown,  terminating  at  point  S.  Construct  the 
rectangular  shaped  front  as  shown  by  setting  the  Compass  to  a  distance 
equal  to  the  length  of  line  B,  and  from  point  R  draw  an  arc  of  a  circle. 


[112] 


[113] 


Set  the  Compass  to  a  distance  equal  to  the  length  of  line  G,  and  from 
point  S  also  draw  an  arc  of  a  circle.  In  order  to  locate  points  U  and  P 
on  the  arcs  just  drawn  it  will  be  necessary  to  have  the  true  diagonal 
length  0  of  the  rectangular  front  which  will  be  found  to  be  O1.  With 
the  Compass  set  to  a  distance  equal  to  the  length  of  O1  draw  an  arc  of 
a  circle  from  point  S,  cutting  the  first  arc  drawn  at  point  U.  With 
the  Compass  set  at  a  distance  equal  to  the  length  of  line  X1,  which  is 
the  true  length  of  line  N,  draw  an  arc  from  point  U,  crossing  the  second 
arc  at  point  P.  Draw  all  bending  lines  as  shown. 

To  draw  the  triangular  shaped  sides  set  the  Compass  at  a  distance 
equal  to  line  L1,  and  from  point  U  draw  an  arc  of  a  circle.  With 
Compass  set  to  a  length  equal  to  line  M1,  which  is  the  true  length  of 
line  M,  draw  an  arc  of  a  circle  from  point  P  intersecting  the  arc  drawn 
from  point  U  at  point  T.  The  back  and  bottom  are  drawn  in  exactly 
the  same  manner.  Make  the  proper  allowance  on  line  M1  of  the  back,  and 
also  on  lines  F  and  G  of  the  triangular  bottom,  for  soldering  surface  as 
shown.  The  series  of  small  circles  shown  on  the  bottom  and  back 
represent  drain  holes.  The  1"  straight  perpendicular  top  edge  of 
triangular  front  C  and  rectangular  fronts  B  and  D  are  to  be  drawn 
with  the  edges  A  at  a  perfect  right  angle  with  lines  B,  C,  and  D. 

It  can  be  seen  in  the  mechanical  drawing,  the  perspective  drawing, 
and  the  development  that  the  perpendicular  top  edges  of  the  triangular 
shaped  sides  are  one  inch  high  in  front,  tapering  to  nothing  in  the  back ; 
therefore,  from  point  U,  with  the  Compass  set  at  a  distance  equal  to  the 
length  of  line  A,  or  1",  draw  the  arc  of  a  circle,  and  with  the  Compass 
set  at  a  distance  equal  to  the  length  of  line  I,  and  using  point  T 
as  a  center,  draw  an  arc  intersecting  the  arc  drawn  from  point  U. 
From  this  point  of  intersection  construct  the  tapering  perpendicular  top 
of  the  triangular  side  as  shown. 

Make  an  allowance  around  the  extreme  top  for  a  reinforcing  wire. 
This  wire,  while  being  inserted,  can  be  made  to  form  a  loop  at  the 
extreme  back  top  corner  to  be  hooked  over  a  small  nail  or  hook  placed 
in  the  corner  of  the  sink  frame,  thus  forming  a  support  for  the  strainer. 


[1141 


[115] 


SCREW  THREADS 

A  curved  line  formed  by  a  point  moving  around  the  surface  of  a 
cylinder,  and  at  the  same  time  advancing  at  a  uniform  speed  along  its 
length,  is  called  a  Helix. 

The  distance  this  point  advances  lengthwise  on  the  surface  of  the 
cylinder  during  each  revolution  is  called  the  Pitch  of  the  helix. 

By  the  careful  examination  of  a  bolt  and  its  thread  it  will  be  seen 
that  the  bolt  is  cylindrical  in  form  and  that  the  thread  in  passing 
around  the  bolt  advances  a  certain  distance  in  every  revolution,  thus 
forming  a  helix.  The  distance  along  the  bolt  that  this  thread  travels 
in  one  revolution  of  the  bolt  is  called  the  pitch  of  the  thread. 

The  method  of  drawing  a  helix  is  shown  in  Figure  I,  Machine  Details. 
The  four-inch  circle  represents  the  diameter  of  the  cylinder  on  which 
the  helix  is  to  be  formed.  The  lines  A  and  G  projecting  upwards  from 
the  horizontal  diameter  of  the  four  inch  circle  represent  a  portion  of 
the  side  of  the  cylinder.  On  line  A  lay  off  the  distance  the  helix  is 
to  travel  lengthwise  in  one  revolution,  or  the  pitch.  Divide  the  circle 
into  an  even  number  of  equal  parts  (twelve  will  be  sufficient)  and 
project  these  division  points  upward  as  shown  by  lines  B,  C,  D,  E, 
and  F. 

Divide  the  pitch  that  has  been  previously  laid  off  on  line  A  into  the 
same  number  of  equal  parts  (twelve),  using  the  same  method  as  shown 
in  Figure  II  of  the  drawing  entitled  Sugar  Scoop.  Project  these  divisions 
horizontally  from  line  A  to  line  G,  passing  them  through  lines  B,  C,  D, 
E,  and  F.  By  the  use  of  the  Irregular  Curve,  draw  the  required  helix 
as  shown,  passing  it  through  the  intersecting  points  of  the  horizontal 
lines  projected  from  the  divisions  on  the  pitch  and  lines  B,  C,  D,  E, 
and  F. 

In  Figure  II  is  shown  a  drawing  of  a  square  thread;  4"  outside 
diameter,  3"  inside  diameter,  with  1"  pitch.  To  show  square  threads 
in  this  manner  requires  considerable  time  and  careful  work.  While 
it  is  advisable  that  the  student  understand  this  method  it  is  advisable 
also  in  the  problems  to  follow  that  he  use  the  more  conventional  method 
shown  in  Figure  III,  or  even  Figure  IV. 

In  Figure  IV  the  thread  is  shown  in  a  manner  that  necessitates 
the  use  of  straight  lines  only.  It  is  not  theoretically  correct,  but  for  all 


[116] 


riG.nz 


DETAILS 


ric.rz: 


[117J 


practical  purposes  it  answers  every  requirement,  as  the  diameter  at  the 
top  and  the  diameter  at  the  bottom  of  the  thread,  as  well  as  the  si/e 
and  pitch  of  the  thread,  can  all  be  accurately  given. 

At  A,  in  Figure  V,  is  shown  a  single  square  thread,  the  outside 
diameter  of  which  is  3",  the  inside  diameter  2^,4",  and  the  depth  of 
the  thread  %"  with  %"  face  arid  a  I1/*/'  pitch.  This  necessarily  has 
the  advantage  over  the  thread  shown  in  Figures  II,  III,  and  IV  of 
being  able  to  travel  exactly  twice  the  distance  of  the  ordinary  thread 
(Fig.  IV)  in  proportion  to  its  size.  It  has  the  disadvantage  of  being 
only  one-half  as  strong. 

To  overcome  this  lack  of  strength  another  thread  of  the  same  size 
and  pitch  is  placed  between  the  single  threads  forming  a  double 
thread,  as  shown  at  B  in  Figure  V.  A  bar  with  a  double  thread  then 
has  the  same  strength  as  a  bar  with  a  single  thread,  and  has  the 
advantage  in  speed,  as  it  travels,  in  one  revolution,  exactly  twice 
the  distance,  as  previously  explained,  of  a  similar  single  thread  screw. 
Owing,  however,  to  the  double  work  accomplished  it  requiries  a  double 
amount  of  power  to  do  this  work.  In  representing  a  common  thread, 
such  as  is  used  on  bolts,  machine  screws,  etc.,  the  conventional  method 
shown  in  Figure  VIII  is  generally  used.  The  pitch  of  the  thread 
shown  in  Figures  VI  and  VII  can  be  determined  only  by  the  required 
number  of  threads  per  inch ;  the  more  threads  per  inch  the  less  will 
be  the  pitch.  When  the  threads  are  standard  the  number  of  threads 
per  inch  can  be  determined  from  a  table.  The  number  is  fixed  for 
any  one  diameter  of  bolt  or  rod.  In  the  case  of  Figures  VI,  VII,  and 
VIII  the  bolt  or  rod  is  V  in  diameter  and  has  8  threads  per  inch. 

Figure  IX  is  an  illustration  of  a  tapering  pipe  thread.  The  object 
of  making  a  pipe  thread  tapering  is  to  insure  a  perfectly  air,  gas,  or 
water  tight  joint.  As  the  size  of  a  pipe  is  always  determined  by  the 
inside  instead  of  the  outside  diameter,  and  as  it  is  necessary  to  construct 
a  thread  on  a  pipe  so  that  its  depth  will  not  materially  weaken  the  pipe, 
it  is  necessary  that  a  standard  for  the  number  of  threads  per  inch  on 
a  pipe  differ  materially  from  the  standard  for  the  number  of  threads 
per  inch  on  a  solid  bolt  or  rod  of  the  same  size.  This  will  be  seen  by 
comparing  the  number  of  threads  per  inch  on  the  1"  pipe  (Fig.  IX) 
with  the  number  of  threads  per  inch  on  a  V  rod  as  in  Figure  VI. 

From  the  dimensions  and  dimension  arcs  given,  the  Hexagonal  and 
Square  Head  Bolts  and  Nuts  can  be  drawn  without  further  explana- 
tion. 


[118] 


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[119] 


HAND  WHEEL 

The  Hand  Wheel  shown  is  such  as  would  be  used  on  a  book-press 
or  steam  valve.  The  section  lines  show  that  it  is  to  be  made  of  cast  iron. 
The  small  oval  section  shown  in  the  spoke  or  arm  at  A  represents  the 
sectional  shape  of  the  arm. 

The  shape  and  size  of  the  rim  B,  the  thickness  of  the  arm  at  rim 
C,  the  thickness  of  the  arm  at  hub  D,  and  the  diameter  and  length 
of  hub  at  each  side  of  center  E,  are  all  plainly  shown  by  a  drawing 
of  a  sectional  side  view. 


[120] 


MACHINE. 
DE  T/1IL  S 

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[121] 


PLAIN  BEARING 

It  is  intended  that  the  student  will  make  drawing's  of  tlie  Plain 
Bearing  in  four  distinct  sizes.  The  dimensions  for  each  bearing  must 
all  be  in  proportion  to  the  diameter  of  the  shaft  for  which  it  is  to  be 
used.  It  will  be  noticed  that  the  diameters  of  the  shafts  for  the  four 
bearings  are  1",  l1^",  2",  and  2^",  respectively. 

The  general  dimensions  such  as  the  length  of  the  bearing  (A),  the 
width  of  the  bearing  (B),  the  diameter  of  the  outside  of  the  bearing 
(E),  and  the  height  of  the  center  of  the  bore  from  the  base  (C)  must 
be  calculated  by  the  student.  Use  the  formulae  given,  which  will  deter- 
mine all  dimensions  of  a  bearing  appropriate  for  the  diameter  of  the 
selected  shaft  or  bore.  The  dimensions  D,  F,  G,  K,  M,  N,  and  P  can 
be  found  at  once  by  referring  to  the  figures  in  line  with  the  different 
shaft  diameters  and  under  the  letter  in  question. 


WRENCH 

The  Wrench  is  designed  by  the  author  so  that  from  the  given 
formulae  all  dimensions  can  be  calculated  for  the  drawings  of  a  series 
of  wrenches,  or  for  the  drawing  of  a  wrench  to  fit  any  desired  hex- 
agonal nut.  It  will  be  seen  that  the  foundation  of  all  dimensions  is  the 
distance  A,  which  can  be  determined  by  taking  the  measurements  of 
the  short  diameter  of  the  nut.  Procure  four  or  five  hexagonal  nuts 
and  from  the  short  diameters  (A)  of  each  make  a  drawing  of  a  wrench 
for  each,  showing  all  dimensions  in  their  proper  location. 


[122] 


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HUTTCH 


[123] 


MONKEY  WRENCH  AND  WOOD  WORKERS'  VISE 

A  Monkey  Wrench  and  Wood  Workers'  Vise  are  tools  -with  which 
all  are  more  or  less  acquainted. 

The  assembly  drawing  of  each  is  given  in  section  and  without  dimen- 
sions. The  detail  drawings  of  these  tools  show  each  and  every  part 
dimensioned,  in  two  or  three  views,  as  the  case  may  be. 

The  object  of  showing  the  assembly  drawings  in  section  is  to  enable 
the  student  to  see  the  exact  location  of  each  part,  as  wTell  as  to  judge 
of  the  work  each  part  has  to  perform.  By  referring  alternately  to  the 
detail  and  the  assembly  the  student  can  readily  determine  the  exaot 
shape,  size,  and  location  of  each  part.  After  the  drawings  have  been 
given  proper  attention  and  study,  the  student  will  be  expected  to  draw 
the  sectional  assembly  with  little  or  no  trouble,  locating  the  position 
of  each  part  from  the  dimensions  of  the  different  parts  given  in  the 
detail  sheet. 

While  the  same  principles  are  involved  in  drawing  either  of  these 
tools,  the  friction  surface  of  the  moving  parts  of  the  wrench  need  not 
be  given  the  attention  that  the  friction  surfaces  of  the  vise  require, 
owing  to  the  different  quality  of  work  it  has  to  perform,  and  to  the 
different  class  of  tools  to  which  it  belongs.  It  will  be  noticed  in  the 
details  of  the  vise  that  the  friction  surfaces,  such  as  the  beam  and  the 
surfaces  of  the  slot  in  the  base  of  the  rear  jaw  in  which  the  beam 
travels,  are  marked  "f."  This  designates  that  these  surfaces  are  to  be 
finished  to  exact  size,  thus  insuring  a  perfect  surface  so  that  the  beam 
may  be  guided  accurately  in  the  direction  it  is  to  travel. 


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[128] 


ARCHITECTURAL   DRAWING 


[129] 


ARCHITECTURAL  DRAWING 

The  particular  Architectural  Problem  herein  given  has  been  selected 
because  in  it  we  are  to  cover  the  points  in  frame  construction  that  are 
apt  to  be  met  with  in  the  designing  and  drawing  of  almost  any  ordinary 
modern  frame  dwelling  house. 

In  designing  a  dwelling  house,  the  first  and  second  floor  plans  must 
be  drawn,  practically  speaking,  as  one  unit;  the  inside  walls  for  different 
stories  in  a  house  should,  for  strength,  be  placed,  as  nearly  as  possible, 
one  above  the  other  in  planning  the  rooms  on  each  floor.  The  location 
of  chimneys  must  be  determined  so  that  they  will  not  conflict  with  the 
walls,  windows,  etc.,  of  the  floor  above  or  below,  as  the  case  may  be. 

The  position  of  the  stair  landings  should  be  definitely  determined 
as  early  as  may  be,  and  other  inside  details  arranged  accordingly. 

The  placing  of  the  bath  room  and  its  plumbing  should  be,  as  nearly 
as  possible,  in  line  with  the  plumbing  of  the  kitchen  and  laundry,  so 
that  all  drainage  pipes  will  lead  directly  to  one  point. 

Ample  closet  accommodation  should  be  made  in  all  upstairs  rooms, 
and  whenever  possible  in  the  upstairs  hallway. 

The  placing  of  all  ordinary  household  furniture,  such  as  a  kitchen 
cabinet,  kitchen  table,  dining  room  table,  dining  room  chairs,  buffet, 
piano,  couch,  beds,  and  dressers,  should  be  considered  as  the  house 
design  proceeds,  so  that  these  articles  may  not  interfere  with  windows, 
doors,  etc.  The  arrangement  of  rooms  should  be  made  so  as  not  -to 
have  any  waste  space,  that  is,  any  space  that  can  not  be  conveniently 
utilized.  The  windows  and  doors  should  be  placed  so  as  to  give  the 
best  light  and  ventilation  possible. 

By  referring  to  the  first  floor  plan  it  will  be  seen  that  the  design  of 
the  house  calls  for  a  front  reception  hall  9'  X  10',  with  an  open  stair- 
way leading  from  it ;  a  living  room  13'  X  13'6",  with  an  open  fireplace ; 
an  open  space,  or  colonnade,  between  the  living  room  and  the  recep- 
tion hall ;  a  dining  room  12'  X  13',  with  sliding  doors  connecting 
it  with  the  living  room.  In  the  dining  room  there  will  be  a  bay  window, 
built-in  china  closets  and  buffet,  over  which  are  small  triple  windows. 
The  kitchen,  9'  X  10',  has  swinging  doors  connecting  it  with  the  dining 
.room.  The  kitchen  contains  a  sink  and  drain  board,  a  chimney  in  the 
wall  for  the  accommodation  of  a  kitchen  stove  or  range,  and  a  small  win- 


[130] 


HVTTON 


[131] 


dow  over  the  sink.  A  pantry  3'6"  X  3'6"  adjoins  the  kitchen.  In  the 
hall  is  an  inside  cellar-way.  On  this  floor  there  is  also  a  back  porch 
4'  X  6'. 

In  the  second  floor  plan  the  design  calls  for  a  front  bedroom, 
10'X14',  with  mantel,  and  a  closet  3'6'/X4/6";  an  alcove  8'  X  10', 
from  which  opens  a  stairway  leading  to  the  attic ;  two  back  bedrooms, 
one  8' X  8',  the  other  10'  X  12'6",  in  each  of  which  is  a  closet  1'G" 
deep  X  4'  wide;  and  a  bathroom  4'6"  X  8',  to  be  provided  with  a 
small  window  on  the  outside  wall.  Just  outside  of  the  bathroom 
partition  is  the  kitchen  chimney  projecting  slightly  into  the  8'  X  8' 
back  bed  room.  From  the  upstairs  center  hall,  which  is  3'G"  wide, 
direct  access  is  made  with  all  upstairs  rooms,  and  also  to  a  hall  closet 
3'6"  X  5'. 

The  building,  with  the  exception  of  the  front  porch  and  bay  win- 
dow, is  seen  on  the  first  floor  plan  to  cover  a  space  of  ground  23'6" 
X  28'.  The  front  porch  extends  across  the  entire  front  of  the  house 
and  is  9'  deep.  The  floor  of  the  porch  is  to  be  made  of  concrete. 

In  the  foundation  plan,  the  concrete  foundation  walls  for  the  porch 
and  basement  partitions  are  to  be  8"  thick,  while  the  thickness  of  the 
main  foundation  wall  is  to  be  10",  with  but  a  5"  wall  for  the  outside 
cellar-way.  The  ceiling  height  of  the  basement,  when  finished,  is  to 
be  7" ;  that  is,  there  must  be  1'  in  the  clear  from  the  concrete  floor  of 
the  basement  to  the  top  of  the  foundation  wall.  A  room  is  to  be  pro- 
vided and  equipped  in  the  basement  for  a  laundry,  as  shown,  and  an 
ample  and  convenient  space  is  left  for  the  storage  of  coal. 

In  drawing  the  foundation  plan,  the  number  of  basement  windows, 
and  the  spacing  of  the  same,  must  receive  considerable  attention. 

If  the  porch  floor  is  to  be  built  solid  from  the  ground  up  the  front 
basement  window  will,  of  necessity,  be  omitted. 

The  point  at  which  a  house  is  sectioned  in  order  to  show  a  proper 
floor  plan  is  just  a  few  inches  above  the  windowsill.  All  doors,  win- 
dows, and  openings  must  be  shown  in  the  plans  at  their  exact  location, 
so  that  in  drawing  the  front,  side,  and  back  elevations  these  locations 
can  be  readily  transferred  to  their  proper  position  in  the  elevation. 

It  will  be  noticed  that  the  front  elevation  is  drawn  to  a  scale  of 
14"  to  the  foot,  thus  permitting  the  showing  of  considerable  detail. 


[132] 


/3ec/Aocfrj 


/?/c 


¥• 


1 


HUTTOH 


[133] 


This  is  the  usual  scale  used  for  such  work,  but  owing  to  the  limited 
space,  the  side  and  back  elevations  are  drawn  to  a  scale  of  %"  to 
the  foot. 

By  referring  to  the  plates  showing  construction,  the  name  of  the 
timbers  used,  as  well  as  the  position  taken  by  each,  can  be  easily 
learned.  The  height  of  the  ceilings  in  the  first  and  second  floors  must 
be  determined  by  the  length  of  the  2"  X  4"  studding  used.  If  the 
usual  eighteen  foot  studding  is  used  it  will  allow  for  about  a  9'6" 
ceiling  on  the  first  floor  with  the  second  floor  ceiling  somewhat  lower, 
or  about  8'3".  If  higher  ceilings  are  desired  longer  studding  will 
be  required. 

With  a  complete  study  of  the  plates,  the  student  should  be  familiar 
with  the  timbers  used,  their  size  and  location,  and  be  able  not  only  to 
draw  this  house,  but  also  to  draw  a  frame  house  of  his  own  design  and 
from  it  to  figure  a  fairly  accurate  material  list. 


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[141] 


[142] 


CO 


[144] 


ELECTRICAL  CONVENTIONS 


The  twenty-six  electrical  conventions  given  are  the  standard  conven- 
tions used  by  the  United  States  Patent  Office.  They  are  not  drawn  to 
any  particular  scale,  for  this  is  not  necessary. 

The  drawing  of  these  conventions  not  only  affords  the  student 
exceptional  practice  in  drawing,  but  also  acquaints  him  with  the  common 
standard  method  of  expressing  easily,  clearly,  and  quickly  his  ideas  along 
electrical  lines. 


[145] 


EL  EC  TRICrfL     C  ONI/EN  T/E/N5 


*- 


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G>S* 


c/ 


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HVTTON 


[146] 


ELECTRICAL     CCNl/ENTIdNS 


c 


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et  /7 


[147] 


HUTTOH. 


ELECTRICAL    CONTENTIONS 


H 


[148] 


EL  EC  TR/C/JL     CnNi/ENTIONS 


III 


B 


o 


e  c 


//-/  ca.  / 


[149] 


PROBLEMS  IN  ELECTRIC  WIRING 


The  following  drawing  problems  in  electricity,  gaspiping,  plumbing, 
and  brickwork  are  intended  especially  for  three  classes  of  students :  for 
those  students  who  anticipate  learning  one  of  these  trades ;  for  those  who 
are  already  serving  their  apprenticeships,  but  also  attending  school, 
part  time;  and  for  the  students  of  Mechanical  Drawing  who  are 
journeymen,  electricians,  plumbers,  or  bricklayers.  It  must  be  under- 
stood, however,  that  the  student  must  first  prepare  himself  properly 
for  this  special  work,  by  completing  and  thoroughly  understanding 
at  least  that  part  of  this  book  up  to  and  including  Wood- Work  Draw- 
ings. It  will  be  much  better,  if  time  permits,  for  the  student  to  com- 
plete the  entire  course  here  given  in  drawing. 


[151] 


BELL  WIRING 

These  problems  in  bell  wiring  are  given  to  acquaint  the  student  with 
the  method  of  laying  out  this  class  of  work. 

In  the  first  bell  wiring  problem  is  shown  the  wiring  for  one  bell 
controlled  by  one  button  switch. 

The  second  problem  is  a  little  more  difficult.  It  consists  of  a  bell  and 
buzzer,  each  controlled  by  a  separate  button  switch,  and  all  connected 
with  but  one  set  of  batteries. 

The  third  problem  is  that  of  a  series  of  bells  controlled  by  but  one 
button  switch,  and  all  connected  with  but  one  set  of  batteries. 


[152] 


BELL    WIRING 


Dry 


/ 


B. 


uzzer* 


[153] 


GASOLINE  ENGINE  WIRING 

There  are  many  methods  used  in  controlling  the  ignition  spark  in  a 
gasoline  engine.  It  may  be  well  for  the  student  to  acquaint  himself  with 
several  of  the  methods,  and  make  drawings  of  each.  The  problem  here 
given,  however,  illustrates  the  general  principles  involved  in  spark  plug 
ignition. 


HOUSE  WIRING 

In  the  problem  of  house  wiring,  an  incandescent  light  controlled  by 
two  separate  switches,  one  on  the  first  and  one  on  the  second  floor,  is 
shown.  It  will  be  noticed  that  the  electrical  conventions  previously  given 
are  made  use  of  in  this  problem  and  also  in  the  gasoline  engine  wiring 
problem.  Note  the  method  of  representing  the  batteries,  the  switches,  the 
incandescent  hall  light,  the  joined  wires,  and  the  crossing  wires.  When 
a  student  has  a  thorough  understanding  of  the  work  given  here  he  should 
be  able  to  lay  out  all  work  within  the  limit  of  his  knowledge  of  the  trade. 


[154] 


GASOLINE    ENGINE    WIRING 


L,  / ret/if 


rfh 


/c  A 


III  H 


is 

t 


-  //c/4 


CO/ 


/ 


To 


HOUSE    WIRING 


cor? 


fro// ecz 


rom 


HUTTON 


[155] 


GAS   PLUMBING   CONVENTIONS 


The  conventional  methods  of  representing  wall  and  drop  lights  for  gas 
are  shown  at  the  top  of  the  plate,  "Gas  Plumbing  Conventions."  It  will 
require  but  little  study  to  distinguish  between  the  convention  for  wall 
lights  and  that  for  drop  lights.  When  the  wall  lights,  or  drop  lights,  or 
both,  are  to  be  shown  connected  with  the  regular  piping,  a  lay  ont,  or 
drawing  similar  to  the  one  shown  in  the  center  of  the  plate,  will  be 
necessary.  In  this  drawing  the  direction  the  pipe  is  to  travel  is  also 
shown  conventionally. 

A  line  indicates  the  pipe  traveling  in  the  direction  that  the  line  is 
drawn. 

A  circle  placed  at  any  point  on  this  line  indicates  that  a  pipe  is  to 
travel  up  from  this  point. 

A  cross  placed  at  any  point  on  this  line  indicates  that  a  pipe  is  to 
travel  down  from  this  point. 

A  cross  inside  of  a  circle  placed  at  any  point  on  this  line  indicates 
that  a  pipe  is  to  travel  both  up  and  down  from  this  point. 

To  make  the  use  of  these  conventions  clear  to  the  student  a  per- 
spective drawing  of  the  problem  in  the  center  of  the  plate  is  shown  at 
the  bottom  of  the  plate. 

By  a  careful  comparison  of  the  perspective  and  the  conventional 
drawings,  the  direction  the  pipes  are  to  travel,  as  well  as  the  location  and 
kind  of  lights  to  be  used  (whether  wall  or  drop  lights)  will  be  plainly 
seen. 

In  making  the  drawings  just  described,  as  well  as  in  drawing  other 
similar  problems,  no  attempt  need  be  made  to  draw  to  any  particular 
scale.  It  is  only  when  such  diagrams  are  drawn  in  connection  with 
building  plans  that  a  scale  is  attempted. 


[156] 


F'L.UMEiINC    COVZ/OVT/O/VS 


I 


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U/o 

O 


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Docun 

x 


[1571 


A  full  size  drawing  for  each  of  the  fourteen  pipe  fittings  shown  must 
be  made.  The  dimensions  can  be  procured  by  measurement  from  the 
castings. 


[159] 


PIPE    FITTINGS 


B 


o 


veer- 


ous 


N  /jo/o/e 


MUTTON 


[160] 


P/PE     riT TINES 


MUTTON 


[161] 


F/F£     FITTINGS 


n  /o  r? 


[162] 


FIFE:   FITTINGS 


L 


[  163  ] 


HUTTON 


PROBLEMS    IN    PLUMBING 


[165] 


HOT  WATER  CONNECTIONS 

There  are  several  methods  of  piping  for  hot  water,  but  the  general 
principle,  practically  speaking,  is  the  same.  The  problem  shown  is 
very  simple.  In  making  the  drawing  the  dimensions  should  be  taken 
from  a  similar  tank,  if  possible.  If  this  is  not  possible,  let  the  tank  be 
5'  0"  high  and  12"  in  diameter,  with  %"  piping  used  throughout. 


[166] 


HOT     WATER   CONNECTIONS 


a,//*/ 


Sera  a  en 


[167] 


LAVATORY  CONNECTIONS 

The  drawing  for  the  lavatory  connections  shown  can  be  made  in  the 
same  manner  as  the  drawing  for  the  hot  water  connections.  If  it  is  not 
convenient  to  take  direct  measurements  from  a  similar  connection,  let 
the  main  drain  pipe  be  4"  in  diameter,  the  vent,  the  drain,  and  the  main 
vent  pipes  2",  the  S-trap  1%",  and  the  bowl  14"  in  diameter  and 
deep. 


[168] 


CONNEC  TIHIN3 


[169] 


HUTTON, 


PROBLEMS  IN  BRICK  WORK 


For  the  making  of  the  drawings  of  the  five  plates  of  brick  work  it 
will  be  necessary  for  the  student  merely  to  study  each  plate  carefully  and 
keep  in  mind  that  a  rough  brick  when  placed  in  a  wall  is  calculated  to 
fill  a  space  2"  X  4"  X  8".  The  actual  size  of  a  rough  brick  is  only  about 
!3/4"  X  33/4"  X  7%",  but  as  the  mortar  is  supposed  to  be  laid  nearly  i/2" 
thick  a  brick  with  its  corresponding  mortar  fills  a  space  in  the  wrall  2"  X 
4"  X  8". 

The  Flemish,  the  Ordinary,  and  the  English  bond  are  shown  by  three 
drawings  of  each.  The  center  drawing  of  each  bond  represents  the 
wall  as  it  would  be  seen  in  the  finished  building. 

The  top  and  bottom  drawings  of  each  bond  represent  a  plan  of  the 
top  and  bottom  courses  (as  the  position  indicates),  the  edges  of  which 
can  be  seen  in  the  center  drawing. 


[171] 


M//7/-L.    SUPPORT 


II      II      II      II      II      II     I'      I 

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M//7LL    SUPPORT 


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HUJTOM 


FLEMISH   BOND 


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DRD/N/JRY    BOND 


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[175] 


ENGLISH  BOND 


\    / /err?    o/  neac/e/" 
»  / 


i      i  ,  '     I  ,  '  _  I_J  _  L_l  _  L_l  _  I_J  _  L 
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[176] 


A     000  037  551     9 


